Lib/zipfile.py

"""
Read and write ZIP files.

XXX references to utf-8 need further investigation.
"""
import io
import os
import re
import importlib.util
import sys
import time
import stat
import shutil
import struct
import binascii


try:
    import zlib # We may need its compression method
    crc32 = zlib.crc32
except ImportError:
    zlib = None
    crc32 = binascii.crc32

try:
    import bz2 # We may need its compression method
except ImportError:
    bz2 = None

try:
    import lzma # We may need its compression method
except ImportError:
    lzma = None

__all__ = ["BadZipFile", "BadZipfile", "error",
           "ZIP_STORED", "ZIP_DEFLATED", "ZIP_BZIP2", "ZIP_LZMA",
           "is_zipfile", "ZipInfo", "ZipFile", "PyZipFile", "LargeZipFile"]

class BadZipFile(Exception):
    pass


class LargeZipFile(Exception):
    """
    Raised when writing a zipfile, the zipfile requires ZIP64 extensions
    and those extensions are disabled.
    """

error = BadZipfile = BadZipFile      # Pre-3.2 compatibility names


ZIP64_LIMIT = (1 << 31) - 1
ZIP_FILECOUNT_LIMIT = (1 << 16) - 1
ZIP_MAX_COMMENT = (1 << 16) - 1

# constants for Zip file compression methods
ZIP_STORED = 0
ZIP_DEFLATED = 8
ZIP_BZIP2 = 12
ZIP_LZMA = 14
# Other ZIP compression methods not supported

DEFAULT_VERSION = 20
ZIP64_VERSION = 45
BZIP2_VERSION = 46
LZMA_VERSION = 63
# we recognize (but not necessarily support) all features up to that version
MAX_EXTRACT_VERSION = 63

# Below are some formats and associated data for reading/writing headers using
# the struct module.  The names and structures of headers/records are those used
# in the PKWARE description of the ZIP file format:
#     http://www.pkware.com/documents/casestudies/APPNOTE.TXT
# (URL valid as of January 2008)

# The "end of central directory" structure, magic number, size, and indices
# (section V.I in the format document)
structEndArchive = b"<4s4H2LH"
stringEndArchive = b"PK\005\006"
sizeEndCentDir = struct.calcsize(structEndArchive)

_ECD_SIGNATURE = 0
_ECD_DISK_NUMBER = 1
_ECD_DISK_START = 2
_ECD_ENTRIES_THIS_DISK = 3
_ECD_ENTRIES_TOTAL = 4
_ECD_SIZE = 5
_ECD_OFFSET = 6
_ECD_COMMENT_SIZE = 7
# These last two indices are not part of the structure as defined in the
# spec, but they are used internally by this module as a convenience
_ECD_COMMENT = 8
_ECD_LOCATION = 9

# The "central directory" structure, magic number, size, and indices
# of entries in the structure (section V.F in the format document)
structCentralDir = "<4s4B4HL2L5H2L"
stringCentralDir = b"PK\001\002"
sizeCentralDir = struct.calcsize(structCentralDir)

# indexes of entries in the central directory structure
_CD_SIGNATURE = 0
_CD_CREATE_VERSION = 1
_CD_CREATE_SYSTEM = 2
_CD_EXTRACT_VERSION = 3
_CD_EXTRACT_SYSTEM = 4
_CD_FLAG_BITS = 5
_CD_COMPRESS_TYPE = 6
_CD_TIME = 7
_CD_DATE = 8
_CD_CRC = 9
_CD_COMPRESSED_SIZE = 10
_CD_UNCOMPRESSED_SIZE = 11
_CD_FILENAME_LENGTH = 12
_CD_EXTRA_FIELD_LENGTH = 13
_CD_COMMENT_LENGTH = 14
_CD_DISK_NUMBER_START = 15
_CD_INTERNAL_FILE_ATTRIBUTES = 16
_CD_EXTERNAL_FILE_ATTRIBUTES = 17
_CD_LOCAL_HEADER_OFFSET = 18

# The "local file header" structure, magic number, size, and indices
# (section V.A in the format document)
structFileHeader = "<4s2B4HL2L2H"
stringFileHeader = b"PK\003\004"
sizeFileHeader = struct.calcsize(structFileHeader)

_FH_SIGNATURE = 0
_FH_EXTRACT_VERSION = 1
_FH_EXTRACT_SYSTEM = 2
_FH_GENERAL_PURPOSE_FLAG_BITS = 3
_FH_COMPRESSION_METHOD = 4
_FH_LAST_MOD_TIME = 5
_FH_LAST_MOD_DATE = 6
_FH_CRC = 7
_FH_COMPRESSED_SIZE = 8
_FH_UNCOMPRESSED_SIZE = 9
_FH_FILENAME_LENGTH = 10
_FH_EXTRA_FIELD_LENGTH = 11

# The "Zip64 end of central directory locator" structure, magic number, and size
structEndArchive64Locator = "<4sLQL"
stringEndArchive64Locator = b"PK\x06\x07"
sizeEndCentDir64Locator = struct.calcsize(structEndArchive64Locator)

# The "Zip64 end of central directory" record, magic number, size, and indices
# (section V.G in the format document)
structEndArchive64 = "<4sQ2H2L4Q"
stringEndArchive64 = b"PK\x06\x06"
sizeEndCentDir64 = struct.calcsize(structEndArchive64)

_CD64_SIGNATURE = 0
_CD64_DIRECTORY_RECSIZE = 1
_CD64_CREATE_VERSION = 2
_CD64_EXTRACT_VERSION = 3
_CD64_DISK_NUMBER = 4
_CD64_DISK_NUMBER_START = 5
_CD64_NUMBER_ENTRIES_THIS_DISK = 6
_CD64_NUMBER_ENTRIES_TOTAL = 7
_CD64_DIRECTORY_SIZE = 8
_CD64_OFFSET_START_CENTDIR = 9

def _check_zipfile(fp):
    try:
        if _EndRecData(fp):
            return True         # file has correct magic number
    except OSError:
        pass
    return False

def is_zipfile(filename):
    """Quickly see if a file is a ZIP file by checking the magic number.

    The filename argument may be a file or file-like object too.
    """
    result = False
    try:
        if hasattr(filename, "read"):
            result = _check_zipfile(fp=filename)
        else:
            with open(filename, "rb") as fp:
                result = _check_zipfile(fp)
    except OSError:
        pass
    return result

def _EndRecData64(fpin, offset, endrec):
    """
    Read the ZIP64 end-of-archive records and use that to update endrec
    """
    try:
        fpin.seek(offset - sizeEndCentDir64Locator, 2)
    except OSError:
        # If the seek fails, the file is not large enough to contain a ZIP64
        # end-of-archive record, so just return the end record we were given.
        return endrec

    data = fpin.read(sizeEndCentDir64Locator)
    if len(data) != sizeEndCentDir64Locator:
        return endrec
    sig, diskno, reloff, disks = struct.unpack(structEndArchive64Locator, data)
    if sig != stringEndArchive64Locator:
        return endrec

    if diskno != 0 or disks != 1:
        raise BadZipFile("zipfiles that span multiple disks are not supported")

    # Assume no 'zip64 extensible data'
    fpin.seek(offset - sizeEndCentDir64Locator - sizeEndCentDir64, 2)
    data = fpin.read(sizeEndCentDir64)
    if len(data) != sizeEndCentDir64:
        return endrec
    sig, sz, create_version, read_version, disk_num, disk_dir, \
        dircount, dircount2, dirsize, diroffset = \
        struct.unpack(structEndArchive64, data)
    if sig != stringEndArchive64:
        return endrec

    # Update the original endrec using data from the ZIP64 record
    endrec[_ECD_SIGNATURE] = sig
    endrec[_ECD_DISK_NUMBER] = disk_num
    endrec[_ECD_DISK_START] = disk_dir
    endrec[_ECD_ENTRIES_THIS_DISK] = dircount
    endrec[_ECD_ENTRIES_TOTAL] = dircount2
    endrec[_ECD_SIZE] = dirsize
    endrec[_ECD_OFFSET] = diroffset
    return endrec


def _EndRecData(fpin):
    """Return data from the "End of Central Directory" record, or None.

    The data is a list of the nine items in the ZIP "End of central dir"
    record followed by a tenth item, the file seek offset of this record."""

    # Determine file size
    fpin.seek(0, 2)
    filesize = fpin.tell()

    # Check to see if this is ZIP file with no archive comment (the
    # "end of central directory" structure should be the last item in the
    # file if this is the case).
    try:
        fpin.seek(-sizeEndCentDir, 2)
    except OSError:
        return None
    data = fpin.read()
    if (len(data) == sizeEndCentDir and
        data[0:4] == stringEndArchive and
        data[-2:] == b"\000\000"):
        # the signature is correct and there's no comment, unpack structure
        endrec = struct.unpack(structEndArchive, data)
        endrec=list(endrec)

        # Append a blank comment and record start offset
        endrec.append(b"")
        endrec.append(filesize - sizeEndCentDir)

        # Try to read the "Zip64 end of central directory" structure
        return _EndRecData64(fpin, -sizeEndCentDir, endrec)

    # Either this is not a ZIP file, or it is a ZIP file with an archive
    # comment.  Search the end of the file for the "end of central directory"
    # record signature. The comment is the last item in the ZIP file and may be
    # up to 64K long.  It is assumed that the "end of central directory" magic
    # number does not appear in the comment.
    maxCommentStart = max(filesize - (1 << 16) - sizeEndCentDir, 0)
    fpin.seek(maxCommentStart, 0)
    data = fpin.read()
    start = data.rfind(stringEndArchive)
    if start >= 0:
        # found the magic number; attempt to unpack and interpret
        recData = data[start:start+sizeEndCentDir]
        if len(recData) != sizeEndCentDir:
            # Zip file is corrupted.
            return None
        endrec = list(struct.unpack(structEndArchive, recData))
        commentSize = endrec[_ECD_COMMENT_SIZE] #as claimed by the zip file
        comment = data[start+sizeEndCentDir:start+sizeEndCentDir+commentSize]
        endrec.append(comment)
        endrec.append(maxCommentStart + start)

        # Try to read the "Zip64 end of central directory" structure
        return _EndRecData64(fpin, maxCommentStart + start - filesize,
                             endrec)

    # Unable to find a valid end of central directory structure
    return None


class ZipInfo (object):
    """Class with attributes describing each file in the ZIP archive."""

    __slots__ = (
        'orig_filename',
        'filename',
        'date_time',
        'compress_type',
        'comment',
        'extra',
        'create_system',
        'create_version',
        'extract_version',
        'reserved',
        'flag_bits',
        'volume',
        'internal_attr',
        'external_attr',
        'header_offset',
        'CRC',
        'compress_size',
        'file_size',
        '_raw_time',
    )

    def __init__(self, filename="NoName", date_time=(1980,1,1,0,0,0)):
        self.orig_filename = filename   # Original file name in archive

        # Terminate the file name at the first null byte.  Null bytes in file
        # names are used as tricks by viruses in archives.
        null_byte = filename.find(chr(0))
        if null_byte >= 0:
            filename = filename[0:null_byte]
        # This is used to ensure paths in generated ZIP files always use
        # forward slashes as the directory separator, as required by the
        # ZIP format specification.
        if os.sep != "/" and os.sep in filename:
            filename = filename.replace(os.sep, "/")

        self.filename = filename        # Normalized file name
        self.date_time = date_time      # year, month, day, hour, min, sec

        if date_time[0] < 1980:
            raise ValueError('ZIP does not support timestamps before 1980')

        # Standard values:
        self.compress_type = ZIP_STORED # Type of compression for the file
        self.comment = b""              # Comment for each file
        self.extra = b""                # ZIP extra data
        if sys.platform == 'win32':
            self.create_system = 0          # System which created ZIP archive
        else:
            # Assume everything else is unix-y
            self.create_system = 3          # System which created ZIP archive
        self.create_version = DEFAULT_VERSION  # Version which created ZIP archive
        self.extract_version = DEFAULT_VERSION # Version needed to extract archive
        self.reserved = 0               # Must be zero
        self.flag_bits = 0              # ZIP flag bits
        self.volume = 0                 # Volume number of file header
        self.internal_attr = 0          # Internal attributes
        self.external_attr = 0          # External file attributes
        # Other attributes are set by class ZipFile:
        # header_offset         Byte offset to the file header
        # CRC                   CRC-32 of the uncompressed file
        # compress_size         Size of the compressed file
        # file_size             Size of the uncompressed file

    def FileHeader(self, zip64=None):
        """Return the per-file header as a string."""
        dt = self.date_time
        dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
        dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
        if self.flag_bits & 0x08:
            # Set these to zero because we write them after the file data
            CRC = compress_size = file_size = 0
        else:
            CRC = self.CRC
            compress_size = self.compress_size
            file_size = self.file_size

        extra = self.extra

        min_version = 0
        if zip64 is None:
            zip64 = file_size > ZIP64_LIMIT or compress_size > ZIP64_LIMIT
        if zip64:
            fmt = '<HHQQ'
            extra = extra + struct.pack(fmt,
                                        1, struct.calcsize(fmt)-4, file_size, compress_size)
        if file_size > ZIP64_LIMIT or compress_size > ZIP64_LIMIT:
            if not zip64:
                raise LargeZipFile("Filesize would require ZIP64 extensions")
            # File is larger than what fits into a 4 byte integer,
            # fall back to the ZIP64 extension
            file_size = 0xffffffff
            compress_size = 0xffffffff
            min_version = ZIP64_VERSION

        if self.compress_type == ZIP_BZIP2:
            min_version = max(BZIP2_VERSION, min_version)
        elif self.compress_type == ZIP_LZMA:
            min_version = max(LZMA_VERSION, min_version)

        self.extract_version = max(min_version, self.extract_version)
        self.create_version = max(min_version, self.create_version)
        filename, flag_bits = self._encodeFilenameFlags()
        header = struct.pack(structFileHeader, stringFileHeader,
                             self.extract_version, self.reserved, flag_bits,
                             self.compress_type, dostime, dosdate, CRC,
                             compress_size, file_size,
                             len(filename), len(extra))
        return header + filename + extra

    def _encodeFilenameFlags(self):
        try:
            return self.filename.encode('ascii'), self.flag_bits
        except UnicodeEncodeError:
            return self.filename.encode('utf-8'), self.flag_bits | 0x800

    def _decodeExtra(self):
        # Try to decode the extra field.
        extra = self.extra
        unpack = struct.unpack
        while len(extra) >= 4:
            tp, ln = unpack('<HH', extra[:4])
            if tp == 1:
                if ln >= 24:
                    counts = unpack('<QQQ', extra[4:28])
                elif ln == 16:
                    counts = unpack('<QQ', extra[4:20])
                elif ln == 8:
                    counts = unpack('<Q', extra[4:12])
                elif ln == 0:
                    counts = ()
                else:
                    raise RuntimeError("Corrupt extra field %s"%(ln,))

                idx = 0

                # ZIP64 extension (large files and/or large archives)
                if self.file_size in (0xffffffffffffffff, 0xffffffff):
                    self.file_size = counts[idx]
                    idx += 1

                if self.compress_size == 0xFFFFFFFF:
                    self.compress_size = counts[idx]
                    idx += 1

                if self.header_offset == 0xffffffff:
                    old = self.header_offset
                    self.header_offset = counts[idx]
                    idx+=1

            extra = extra[ln+4:]


class _ZipDecrypter:
    """Class to handle decryption of files stored within a ZIP archive.

    ZIP supports a password-based form of encryption. Even though known
    plaintext attacks have been found against it, it is still useful
    to be able to get data out of such a file.

    Usage:
        zd = _ZipDecrypter(mypwd)
        plain_char = zd(cypher_char)
        plain_text = map(zd, cypher_text)
    """

    def _GenerateCRCTable():
        """Generate a CRC-32 table.

        ZIP encryption uses the CRC32 one-byte primitive for scrambling some
        internal keys. We noticed that a direct implementation is faster than
        relying on binascii.crc32().
        """
        poly = 0xedb88320
        table = [0] * 256
        for i in range(256):
            crc = i
            for j in range(8):
                if crc & 1:
                    crc = ((crc >> 1) & 0x7FFFFFFF) ^ poly
                else:
                    crc = ((crc >> 1) & 0x7FFFFFFF)
            table[i] = crc
        return table
    crctable = None

    def _crc32(self, ch, crc):
        """Compute the CRC32 primitive on one byte."""
        return ((crc >> 8) & 0xffffff) ^ self.crctable[(crc ^ ch) & 0xff]

    def __init__(self, pwd):
        if _ZipDecrypter.crctable is None:
            _ZipDecrypter.crctable = _ZipDecrypter._GenerateCRCTable()
        self.key0 = 305419896
        self.key1 = 591751049
        self.key2 = 878082192
        for p in pwd:
            self._UpdateKeys(p)

    def _UpdateKeys(self, c):
        self.key0 = self._crc32(c, self.key0)
        self.key1 = (self.key1 + (self.key0 & 255)) & 4294967295
        self.key1 = (self.key1 * 134775813 + 1) & 4294967295
        self.key2 = self._crc32((self.key1 >> 24) & 255, self.key2)

    def __call__(self, c):
        """Decrypt a single character."""
        assert isinstance(c, int)
        k = self.key2 | 2
        c = c ^ (((k * (k^1)) >> 8) & 255)
        self._UpdateKeys(c)
        return c


class LZMACompressor:

    def __init__(self):
        self._comp = None

    def _init(self):
        props = lzma._encode_filter_properties({'id': lzma.FILTER_LZMA1})
        self._comp = lzma.LZMACompressor(lzma.FORMAT_RAW, filters=[
            lzma._decode_filter_properties(lzma.FILTER_LZMA1, props)
        ])
        return struct.pack('<BBH', 9, 4, len(props)) + props

    def compress(self, data):
        if self._comp is None:
            return self._init() + self._comp.compress(data)
        return self._comp.compress(data)

    def flush(self):
        if self._comp is None:
            return self._init() + self._comp.flush()
        return self._comp.flush()


class LZMADecompressor:

    def __init__(self):
        self._decomp = None
        self._unconsumed = b''
        self.eof = False

    def decompress(self, data):
        if self._decomp is None:
            self._unconsumed += data
            if len(self._unconsumed) <= 4:
                return b''
            psize, = struct.unpack('<H', self._unconsumed[2:4])
            if len(self._unconsumed) <= 4 + psize:
                return b''

            self._decomp = lzma.LZMADecompressor(lzma.FORMAT_RAW, filters=[
                lzma._decode_filter_properties(lzma.FILTER_LZMA1,
                                               self._unconsumed[4:4 + psize])
            ])
            data = self._unconsumed[4 + psize:]
            del self._unconsumed

        result = self._decomp.decompress(data)
        self.eof = self._decomp.eof
        return result


compressor_names = {
    0: 'store',
    1: 'shrink',
    2: 'reduce',
    3: 'reduce',
    4: 'reduce',
    5: 'reduce',
    6: 'implode',
    7: 'tokenize',
    8: 'deflate',
    9: 'deflate64',
    10: 'implode',
    12: 'bzip2',
    14: 'lzma',
    18: 'terse',
    19: 'lz77',
    97: 'wavpack',
    98: 'ppmd',
}

def _check_compression(compression):
    if compression == ZIP_STORED:
        pass
    elif compression == ZIP_DEFLATED:
        if not zlib:
            raise RuntimeError(
                "Compression requires the (missing) zlib module")
    elif compression == ZIP_BZIP2:
        if not bz2:
            raise RuntimeError(
                "Compression requires the (missing) bz2 module")
    elif compression == ZIP_LZMA:
        if not lzma:
            raise RuntimeError(
                "Compression requires the (missing) lzma module")
    else:
        raise RuntimeError("That compression method is not supported")


def _get_compressor(compress_type):
    if compress_type == ZIP_DEFLATED:
        return zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
                                zlib.DEFLATED, -15)
    elif compress_type == ZIP_BZIP2:
        return bz2.BZ2Compressor()
    elif compress_type == ZIP_LZMA:
        return LZMACompressor()
    else:
        return None


def _get_decompressor(compress_type):
    if compress_type == ZIP_STORED:
        return None
    elif compress_type == ZIP_DEFLATED:
        return zlib.decompressobj(-15)
    elif compress_type == ZIP_BZIP2:
        return bz2.BZ2Decompressor()
    elif compress_type == ZIP_LZMA:
        return LZMADecompressor()
    else:
        descr = compressor_names.get(compress_type)
        if descr:
            raise NotImplementedError("compression type %d (%s)" % (compress_type, descr))
        else:
            raise NotImplementedError("compression type %d" % (compress_type,))


class ZipExtFile(io.BufferedIOBase):
    """File-like object for reading an archive member.
       Is returned by ZipFile.open().
    """

    # Max size supported by decompressor.
    MAX_N = 1 << 31 - 1

    # Read from compressed files in 4k blocks.
    MIN_READ_SIZE = 4096

    # Search for universal newlines or line chunks.
    PATTERN = re.compile(br'^(?P<chunk>[^\r\n]+)|(?P<newline>\n|\r\n?)')

    def __init__(self, fileobj, mode, zipinfo, decrypter=None,
                 close_fileobj=False):
        self._fileobj = fileobj
        self._decrypter = decrypter
        self._close_fileobj = close_fileobj

        self._compress_type = zipinfo.compress_type
        self._compress_left = zipinfo.compress_size
        self._left = zipinfo.file_size

        self._decompressor = _get_decompressor(self._compress_type)

        self._eof = False
        self._readbuffer = b''
        self._offset = 0

        self._universal = 'U' in mode
        self.newlines = None

        # Adjust read size for encrypted files since the first 12 bytes
        # are for the encryption/password information.
        if self._decrypter is not None:
            self._compress_left -= 12

        self.mode = mode
        self.name = zipinfo.filename

        if hasattr(zipinfo, 'CRC'):
            self._expected_crc = zipinfo.CRC
            self._running_crc = crc32(b'') & 0xffffffff
        else:
            self._expected_crc = None

    def readline(self, limit=-1):
        """Read and return a line from the stream.

        If limit is specified, at most limit bytes will be read.
        """

        if not self._universal and limit < 0:
            # Shortcut common case - newline found in buffer.
            i = self._readbuffer.find(b'\n', self._offset) + 1
            if i > 0:
                line = self._readbuffer[self._offset: i]
                self._offset = i
                return line

        if not self._universal:
            return io.BufferedIOBase.readline(self, limit)

        line = b''
        while limit < 0 or len(line) < limit:
            readahead = self.peek(2)
            if readahead == b'':
                return line

            #
            # Search for universal newlines or line chunks.
            #
            # The pattern returns either a line chunk or a newline, but not
            # both. Combined with peek(2), we are assured that the sequence
            # '\r\n' is always retrieved completely and never split into
            # separate newlines - '\r', '\n' due to coincidental readaheads.
            #
            match = self.PATTERN.search(readahead)
            newline = match.group('newline')
            if newline is not None:
                if self.newlines is None:
                    self.newlines = []
                if newline not in self.newlines:
                    self.newlines.append(newline)
                self._offset += len(newline)
                return line + b'\n'

            chunk = match.group('chunk')
            if limit >= 0:
                chunk = chunk[: limit - len(line)]

            self._offset += len(chunk)
            line += chunk

        return line

    def peek(self, n=1):
        """Returns buffered bytes without advancing the position."""
        if n > len(self._readbuffer) - self._offset:
            chunk = self.read(n)
            if len(chunk) > self._offset:
                self._readbuffer = chunk + self._readbuffer[self._offset:]
                self._offset = 0
            else:
                self._offset -= len(chunk)

        # Return up to 512 bytes to reduce allocation overhead for tight loops.
        return self._readbuffer[self._offset: self._offset + 512]

    def readable(self):
        return True

    def read(self, n=-1):
        """Read and return up to n bytes.
        If the argument is omitted, None, or negative, data is read and returned until EOF is reached..
        """
        if n is None or n < 0:
            buf = self._readbuffer[self._offset:]
            self._readbuffer = b''
            self._offset = 0
            while not self._eof:
                buf += self._read1(self.MAX_N)
            return buf

        end = n + self._offset
        if end < len(self._readbuffer):
            buf = self._readbuffer[self._offset:end]
            self._offset = end
            return buf

        n = end - len(self._readbuffer)
        buf = self._readbuffer[self._offset:]
        self._readbuffer = b''
        self._offset = 0
        while n > 0 and not self._eof:
            data = self._read1(n)
            if n < len(data):
                self._readbuffer = data
                self._offset = n
                buf += data[:n]
                break
            buf += data
            n -= len(data)
        return buf

    def _update_crc(self, newdata):
        # Update the CRC using the given data.
        if self._expected_crc is None:
            # No need to compute the CRC if we don't have a reference value
            return
        self._running_crc = crc32(newdata, self._running_crc) & 0xffffffff
        # Check the CRC if we're at the end of the file
        if self._eof and self._running_crc != self._expected_crc:
            raise BadZipFile("Bad CRC-32 for file %r" % self.name)

    def read1(self, n):
        """Read up to n bytes with at most one read() system call."""

        if n is None or n < 0:
            buf = self._readbuffer[self._offset:]
            self._readbuffer = b''
            self._offset = 0
            while not self._eof:
                data = self._read1(self.MAX_N)
                if data:
                    buf += data
                    break
            return buf

        end = n + self._offset
        if end < len(self._readbuffer):
            buf = self._readbuffer[self._offset:end]
            self._offset = end
            return buf

        n = end - len(self._readbuffer)
        buf = self._readbuffer[self._offset:]
        self._readbuffer = b''
        self._offset = 0
        if n > 0:
            while not self._eof:
                data = self._read1(n)
                if n < len(data):
                    self._readbuffer = data
                    self._offset = n
                    buf += data[:n]
                    break
                if data:
                    buf += data
                    break
        return buf

    def _read1(self, n):
        # Read up to n compressed bytes with at most one read() system call,
        # decrypt and decompress them.
        if self._eof or n <= 0:
            return b''

        # Read from file.
        if self._compress_type == ZIP_DEFLATED:
            ## Handle unconsumed data.
            data = self._decompressor.unconsumed_tail
            if n > len(data):
                data += self._read2(n - len(data))
        else:
            data = self._read2(n)

        if self._compress_type == ZIP_STORED:
            self._eof = self._compress_left <= 0
        elif self._compress_type == ZIP_DEFLATED:
            n = max(n, self.MIN_READ_SIZE)
            data = self._decompressor.decompress(data, n)
            self._eof = (self._decompressor.eof or
                         self._compress_left <= 0 and
                         not self._decompressor.unconsumed_tail)
            if self._eof:
                data += self._decompressor.flush()
        else:
            data = self._decompressor.decompress(data)
            self._eof = self._decompressor.eof or self._compress_left <= 0

        data = data[:self._left]
        self._left -= len(data)
        if self._left <= 0:
            self._eof = True
        self._update_crc(data)
        return data

    def _read2(self, n):
        if self._compress_left <= 0:
            return b''

        n = max(n, self.MIN_READ_SIZE)
        n = min(n, self._compress_left)

        data = self._fileobj.read(n)
        self._compress_left -= len(data)
        if not data:
            raise EOFError

        if self._decrypter is not None:
            data = bytes(map(self._decrypter, data))
        return data

    def close(self):
        try:
            if self._close_fileobj:
                self._fileobj.close()
        finally:
            super().close()


class ZipFile:
    """ Class with methods to open, read, write, close, list zip files.

    z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=True)

    file: Either the path to the file, or a file-like object.
          If it is a path, the file will be opened and closed by ZipFile.
    mode: The mode can be either read "r", write "w" or append "a".
    compression: ZIP_STORED (no compression), ZIP_DEFLATED (requires zlib),
                 ZIP_BZIP2 (requires bz2) or ZIP_LZMA (requires lzma).
    allowZip64: if True ZipFile will create files with ZIP64 extensions when
                needed, otherwise it will raise an exception when this would
                be necessary.

    """

    fp = None                   # Set here since __del__ checks it
    _windows_illegal_name_trans_table = None

    def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=True):
        """Open the ZIP file with mode read "r", write "w" or append "a"."""
        if mode not in ("r", "w", "a"):
            raise RuntimeError('ZipFile() requires mode "r", "w", or "a"')

        _check_compression(compression)

        self._allowZip64 = allowZip64
        self._didModify = False
        self.debug = 0  # Level of printing: 0 through 3
        self.NameToInfo = {}    # Find file info given name
        self.filelist = []      # List of ZipInfo instances for archive
        self.compression = compression  # Method of compression
        self.mode = key = mode.replace('b', '')[0]
        self.pwd = None
        self._comment = b''

        # Check if we were passed a file-like object
        if isinstance(file, str):
            # No, it's a filename
            self._filePassed = 0
            self.filename = file
            modeDict = {'r' : 'rb', 'w': 'wb', 'a' : 'r+b'}
            try:
                self.fp = io.open(file, modeDict[mode])
            except OSError:
                if mode == 'a':
                    mode = key = 'w'
                    self.fp = io.open(file, modeDict[mode])
                else:
                    raise
        else:
            self._filePassed = 1
            self.fp = file
            self.filename = getattr(file, 'name', None)

        try:
            if key == 'r':
                self._RealGetContents()
            elif key == 'w':
                # set the modified flag so central directory gets written
                # even if no files are added to the archive
                self._didModify = True
            elif key == 'a':
                try:
                    # See if file is a zip file
                    self._RealGetContents()
                    # seek to start of directory and overwrite
                    self.fp.seek(self.start_dir, 0)
                except BadZipFile:
                    # file is not a zip file, just append
                    self.fp.seek(0, 2)

                    # set the modified flag so central directory gets written
                    # even if no files are added to the archive
                    self._didModify = True
            else:
                raise RuntimeError('Mode must be "r", "w" or "a"')
        except:
            fp = self.fp
            self.fp = None
            if not self._filePassed:
                fp.close()
            raise

    def __enter__(self):
        return self

    def __exit__(self, type, value, traceback):
        self.close()

    def _RealGetContents(self):
        """Read in the table of contents for the ZIP file."""
        fp = self.fp
        try:
            endrec = _EndRecData(fp)
        except OSError:
            raise BadZipFile("File is not a zip file")
        if not endrec:
            raise BadZipFile("File is not a zip file")
        if self.debug > 1:
            print(endrec)
        size_cd = endrec[_ECD_SIZE]             # bytes in central directory
        offset_cd = endrec[_ECD_OFFSET]         # offset of central directory
        self._comment = endrec[_ECD_COMMENT]    # archive comment

        # "concat" is zero, unless zip was concatenated to another file
        concat = endrec[_ECD_LOCATION] - size_cd - offset_cd
        if endrec[_ECD_SIGNATURE] == stringEndArchive64:
            # If Zip64 extension structures are present, account for them
            concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator)

        if self.debug > 2:
            inferred = concat + offset_cd
            print("given, inferred, offset", offset_cd, inferred, concat)
        # self.start_dir:  Position of start of central directory
        self.start_dir = offset_cd + concat
        fp.seek(self.start_dir, 0)
        data = fp.read(size_cd)
        fp = io.BytesIO(data)
        total = 0
        while total < size_cd:
            centdir = fp.read(sizeCentralDir)
            if len(centdir) != sizeCentralDir:
                raise BadZipFile("Truncated central directory")
            centdir = struct.unpack(structCentralDir, centdir)
            if centdir[_CD_SIGNATURE] != stringCentralDir:
                raise BadZipFile("Bad magic number for central directory")
            if self.debug > 2:
                print(centdir)
            filename = fp.read(centdir[_CD_FILENAME_LENGTH])
            flags = centdir[5]
            if flags & 0x800:
                # UTF-8 file names extension
                filename = filename.decode('utf-8')
            else:
                # Historical ZIP filename encoding
                filename = filename.decode('cp437')
            # Create ZipInfo instance to store file information
            x = ZipInfo(filename)
            x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH])
            x.comment = fp.read(centdir[_CD_COMMENT_LENGTH])
            x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET]
            (x.create_version, x.create_system, x.extract_version, x.reserved,
             x.flag_bits, x.compress_type, t, d,
             x.CRC, x.compress_size, x.file_size) = centdir[1:12]
            if x.extract_version > MAX_EXTRACT_VERSION:
                raise NotImplementedError("zip file version %.1f" %
                                          (x.extract_version / 10))
            x.volume, x.internal_attr, x.external_attr = centdir[15:18]
            # Convert date/time code to (year, month, day, hour, min, sec)
            x._raw_time = t
            x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F,
                            t>>11, (t>>5)&0x3F, (t&0x1F) * 2 )

            x._decodeExtra()
            x.header_offset = x.header_offset + concat
            self.filelist.append(x)
            self.NameToInfo[x.filename] = x

            # update total bytes read from central directory
            total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH]
                     + centdir[_CD_EXTRA_FIELD_LENGTH]
                     + centdir[_CD_COMMENT_LENGTH])

            if self.debug > 2:
                print("total", total)


    def namelist(self):
        """Return a list of file names in the archive."""
        return [data.filename for data in self.filelist]

    def infolist(self):
        """Return a list of class ZipInfo instances for files in the
        archive."""
        return self.filelist

    def printdir(self, file=None):
        """Print a table of contents for the zip file."""
        print("%-46s %19s %12s" % ("File Name", "Modified    ", "Size"),
              file=file)
        for zinfo in self.filelist:
            date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
            print("%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size),
                  file=file)

    def testzip(self):
        """Read all the files and check the CRC."""
        chunk_size = 2 ** 20
        for zinfo in self.filelist:
            try:
                # Read by chunks, to avoid an OverflowError or a
                # MemoryError with very large embedded files.
                with self.open(zinfo.filename, "r") as f:
                    while f.read(chunk_size):     # Check CRC-32
                        pass
            except BadZipFile:
                return zinfo.filename

    def getinfo(self, name):
        """Return the instance of ZipInfo given 'name'."""
        info = self.NameToInfo.get(name)
        if info is None:
            raise KeyError(
                'There is no item named %r in the archive' % name)

        return info

    def setpassword(self, pwd):
        """Set default password for encrypted files."""
        if pwd and not isinstance(pwd, bytes):
            raise TypeError("pwd: expected bytes, got %s" % type(pwd))
        if pwd:
            self.pwd = pwd
        else:
            self.pwd = None

    @property
    def comment(self):
        """The comment text associated with the ZIP file."""
        return self._comment

    @comment.setter
    def comment(self, comment):
        if not isinstance(comment, bytes):
            raise TypeError("comment: expected bytes, got %s" % type(comment))
        # check for valid comment length
        if len(comment) > ZIP_MAX_COMMENT:
            import warnings
            warnings.warn('Archive comment is too long; truncating to %d bytes'
                          % ZIP_MAX_COMMENT, stacklevel=2)
            comment = comment[:ZIP_MAX_COMMENT]
        self._comment = comment
        self._didModify = True

    def read(self, name, pwd=None):
        """Return file bytes (as a string) for name."""
        with self.open(name, "r", pwd) as fp:
            return fp.read()

    def open(self, name, mode="r", pwd=None):
        """Return file-like object for 'name'."""
        if mode not in ("r", "U", "rU"):
            raise RuntimeError('open() requires mode "r", "U", or "rU"')
        if 'U' in mode:
            import warnings
            warnings.warn("'U' mode is deprecated",
                          DeprecationWarning, 2)
        if pwd and not isinstance(pwd, bytes):
            raise TypeError("pwd: expected bytes, got %s" % type(pwd))
        if not self.fp:
            raise RuntimeError(
                "Attempt to read ZIP archive that was already closed")

        # Only open a new file for instances where we were not
        # given a file object in the constructor
        if self._filePassed:
            zef_file = self.fp
        else:
            zef_file = io.open(self.filename, 'rb')

        try:
            # Make sure we have an info object
            if isinstance(name, ZipInfo):
                # 'name' is already an info object
                zinfo = name
            else:
                # Get info object for name
                zinfo = self.getinfo(name)
            zef_file.seek(zinfo.header_offset, 0)

            # Skip the file header:
            fheader = zef_file.read(sizeFileHeader)
            if len(fheader) != sizeFileHeader:
                raise BadZipFile("Truncated file header")
            fheader = struct.unpack(structFileHeader, fheader)
            if fheader[_FH_SIGNATURE] != stringFileHeader:
                raise BadZipFile("Bad magic number for file header")

            fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
            if fheader[_FH_EXTRA_FIELD_LENGTH]:
                zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])

            if zinfo.flag_bits & 0x20:
                # Zip 2.7: compressed patched data
                raise NotImplementedError("compressed patched data (flag bit 5)")

            if zinfo.flag_bits & 0x40:
                # strong encryption
                raise NotImplementedError("strong encryption (flag bit 6)")

            if zinfo.flag_bits & 0x800:
                # UTF-8 filename
                fname_str = fname.decode("utf-8")
            else:
                fname_str = fname.decode("cp437")

            if fname_str != zinfo.orig_filename:
                raise BadZipFile(
                    'File name in directory %r and header %r differ.'
                    % (zinfo.orig_filename, fname))

            # check for encrypted flag & handle password
            is_encrypted = zinfo.flag_bits & 0x1
            zd = None
            if is_encrypted:
                if not pwd:
                    pwd = self.pwd
                if not pwd:
                    raise RuntimeError("File %s is encrypted, password "
                                       "required for extraction" % name)

                zd = _ZipDecrypter(pwd)
                # The first 12 bytes in the cypher stream is an encryption header
                #  used to strengthen the algorithm. The first 11 bytes are
                #  completely random, while the 12th contains the MSB of the CRC,
                #  or the MSB of the file time depending on the header type
                #  and is used to check the correctness of the password.
                header = zef_file.read(12)
                h = list(map(zd, header[0:12]))
                if zinfo.flag_bits & 0x8:
                    # compare against the file type from extended local headers
                    check_byte = (zinfo._raw_time >> 8) & 0xff
                else:
                    # compare against the CRC otherwise
                    check_byte = (zinfo.CRC >> 24) & 0xff
                if h[11] != check_byte:
                    raise RuntimeError("Bad password for file", name)

            return ZipExtFile(zef_file, mode, zinfo, zd,
                              close_fileobj=not self._filePassed)
        except:
            if not self._filePassed:
                zef_file.close()
            raise

    def extract(self, member, path=None, pwd=None):
        """Extract a member from the archive to the current working directory,
           using its full name. Its file information is extracted as accurately
           as possible. `member' may be a filename or a ZipInfo object. You can
           specify a different directory using `path'.
        """
        if not isinstance(member, ZipInfo):
            member = self.getinfo(member)

        if path is None:
            path = os.getcwd()

        return self._extract_member(member, path, pwd)

    def extractall(self, path=None, members=None, pwd=None):
        """Extract all members from the archive to the current working
           directory. `path' specifies a different directory to extract to.
           `members' is optional and must be a subset of the list returned
           by namelist().
        """
        if members is None:
            members = self.namelist()

        for zipinfo in members:
            self.extract(zipinfo, path, pwd)

    @classmethod
    def _sanitize_windows_name(cls, arcname, pathsep):
        """Replace bad characters and remove trailing dots from parts."""
        table = cls._windows_illegal_name_trans_table
        if not table:
            illegal = ':<>|"?*'
            table = str.maketrans(illegal, '_' * len(illegal))
            cls._windows_illegal_name_trans_table = table
        arcname = arcname.translate(table)
        # remove trailing dots
        arcname = (x.rstrip('.') for x in arcname.split(pathsep))
        # rejoin, removing empty parts.
        arcname = pathsep.join(x for x in arcname if x)
        return arcname

    def _extract_member(self, member, targetpath, pwd):
        """Extract the ZipInfo object 'member' to a physical
           file on the path targetpath.
        """
        # build the destination pathname, replacing
        # forward slashes to platform specific separators.
        arcname = member.filename.replace('/', os.path.sep)

        if os.path.altsep:
            arcname = arcname.replace(os.path.altsep, os.path.sep)
        # interpret absolute pathname as relative, remove drive letter or
        # UNC path, redundant separators, "." and ".." components.
        arcname = os.path.splitdrive(arcname)[1]
        invalid_path_parts = ('', os.path.curdir, os.path.pardir)
        arcname = os.path.sep.join(x for x in arcname.split(os.path.sep)
                                   if x not in invalid_path_parts)
        if os.path.sep == '\\':
            # filter illegal characters on Windows
            arcname = self._sanitize_windows_name(arcname, os.path.sep)

        targetpath = os.path.join(targetpath, arcname)
        targetpath = os.path.normpath(targetpath)

        # Create all upper directories if necessary.
        upperdirs = os.path.dirname(targetpath)
        if upperdirs and not os.path.exists(upperdirs):
            os.makedirs(upperdirs)

        if member.filename[-1] == '/':
            if not os.path.isdir(targetpath):
                os.mkdir(targetpath)
            return targetpath

        with self.open(member, pwd=pwd) as source, \
             open(targetpath, "wb") as target:
            shutil.copyfileobj(source, target)

        return targetpath

    def _writecheck(self, zinfo):
        """Check for errors before writing a file to the archive."""
        if zinfo.filename in self.NameToInfo:
            import warnings
            warnings.warn('Duplicate name: %r' % zinfo.filename, stacklevel=3)
        if self.mode not in ("w", "a"):
            raise RuntimeError('write() requires mode "w" or "a"')
        if not self.fp:
            raise RuntimeError(
                "Attempt to write ZIP archive that was already closed")
        _check_compression(zinfo.compress_type)
        if not self._allowZip64:
            requires_zip64 = None
            if len(self.filelist) >= ZIP_FILECOUNT_LIMIT:
                requires_zip64 = "Files count"
            elif zinfo.file_size > ZIP64_LIMIT:
                requires_zip64 = "Filesize"
            elif zinfo.header_offset > ZIP64_LIMIT:
                requires_zip64 = "Zipfile size"
            if requires_zip64:
                raise LargeZipFile(requires_zip64 +
                                   " would require ZIP64 extensions")

    def write(self, filename, arcname=None, compress_type=None):
        """Put the bytes from filename into the archive under the name
        arcname."""
        if not self.fp:
            raise RuntimeError(
                "Attempt to write to ZIP archive that was already closed")

        st = os.stat(filename)
        isdir = stat.S_ISDIR(st.st_mode)
        mtime = time.localtime(st.st_mtime)
        date_time = mtime[0:6]
        # Create ZipInfo instance to store file information
        if arcname is None:
            arcname = filename
        arcname = os.path.normpath(os.path.splitdrive(arcname)[1])
        while arcname[0] in (os.sep, os.altsep):
            arcname = arcname[1:]
        if isdir:
            arcname += '/'
        zinfo = ZipInfo(arcname, date_time)
        zinfo.external_attr = (st[0] & 0xFFFF) << 16      # Unix attributes
        if compress_type is None:
            zinfo.compress_type = self.compression
        else:
            zinfo.compress_type = compress_type

        zinfo.file_size = st.st_size
        zinfo.flag_bits = 0x00
        zinfo.header_offset = self.fp.tell()    # Start of header bytes
        if zinfo.compress_type == ZIP_LZMA:
            # Compressed data includes an end-of-stream (EOS) marker
            zinfo.flag_bits |= 0x02

        self._writecheck(zinfo)
        self._didModify = True

        if isdir:
            zinfo.file_size = 0
            zinfo.compress_size = 0
            zinfo.CRC = 0
            zinfo.external_attr |= 0x10  # MS-DOS directory flag
            self.filelist.append(zinfo)
            self.NameToInfo[zinfo.filename] = zinfo
            self.fp.write(zinfo.FileHeader(False))
            return

        cmpr = _get_compressor(zinfo.compress_type)
        with open(filename, "rb") as fp:
            # Must overwrite CRC and sizes with correct data later
            zinfo.CRC = CRC = 0
            zinfo.compress_size = compress_size = 0
            # Compressed size can be larger than uncompressed size
            zip64 = self._allowZip64 and \
                zinfo.file_size * 1.05 > ZIP64_LIMIT
            self.fp.write(zinfo.FileHeader(zip64))
            file_size = 0
            while 1:
                buf = fp.read(1024 * 8)
                if not buf:
                    break
                file_size = file_size + len(buf)
                CRC = crc32(buf, CRC) & 0xffffffff
                if cmpr:
                    buf = cmpr.compress(buf)
                    compress_size = compress_size + len(buf)
                self.fp.write(buf)
        if cmpr:
            buf = cmpr.flush()
            compress_size = compress_size + len(buf)
            self.fp.write(buf)
            zinfo.compress_size = compress_size
        else:
            zinfo.compress_size = file_size
        zinfo.CRC = CRC
        zinfo.file_size = file_size
        if not zip64 and self._allowZip64:
            if file_size > ZIP64_LIMIT:
                raise RuntimeError('File size has increased during compressing')
            if compress_size > ZIP64_LIMIT:
                raise RuntimeError('Compressed size larger than uncompressed size')
        # Seek backwards and write file header (which will now include
        # correct CRC and file sizes)
        position = self.fp.tell()       # Preserve current position in file
        self.fp.seek(zinfo.header_offset, 0)
        self.fp.write(zinfo.FileHeader(zip64))
        self.fp.seek(position, 0)
        self.filelist.append(zinfo)
        self.NameToInfo[zinfo.filename] = zinfo

    def writestr(self, zinfo_or_arcname, data, compress_type=None):
        """Write a file into the archive.  The contents is 'data', which
        may be either a 'str' or a 'bytes' instance; if it is a 'str',
        it is encoded as UTF-8 first.
        'zinfo_or_arcname' is either a ZipInfo instance or
        the name of the file in the archive."""
        if isinstance(data, str):
            data = data.encode("utf-8")
        if not isinstance(zinfo_or_arcname, ZipInfo):
            zinfo = ZipInfo(filename=zinfo_or_arcname,
                            date_time=time.localtime(time.time())[:6])
            zinfo.compress_type = self.compression
            if zinfo.filename[-1] == '/':
                zinfo.external_attr = 0o40775 << 16   # drwxrwxr-x
                zinfo.external_attr |= 0x10           # MS-DOS directory flag
            else:
                zinfo.external_attr = 0o600 << 16     # ?rw-------
        else:
            zinfo = zinfo_or_arcname

        if not self.fp:
            raise RuntimeError(
                "Attempt to write to ZIP archive that was already closed")

        zinfo.file_size = len(data)            # Uncompressed size
        zinfo.header_offset = self.fp.tell()    # Start of header data
        if compress_type is not None:
            zinfo.compress_type = compress_type
        if zinfo.compress_type == ZIP_LZMA:
            # Compressed data includes an end-of-stream (EOS) marker
            zinfo.flag_bits |= 0x02

        self._writecheck(zinfo)
        self._didModify = True
        zinfo.CRC = crc32(data) & 0xffffffff       # CRC-32 checksum
        co = _get_compressor(zinfo.compress_type)
        if co:
            data = co.compress(data) + co.flush()
            zinfo.compress_size = len(data)    # Compressed size
        else:
            zinfo.compress_size = zinfo.file_size
        zip64 = zinfo.file_size > ZIP64_LIMIT or \
            zinfo.compress_size > ZIP64_LIMIT
        if zip64 and not self._allowZip64:
            raise LargeZipFile("Filesize would require ZIP64 extensions")
        self.fp.write(zinfo.FileHeader(zip64))
        self.fp.write(data)
        if zinfo.flag_bits & 0x08:
            # Write CRC and file sizes after the file data
            fmt = '<LQQ' if zip64 else '<LLL'
            self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size,
                                      zinfo.file_size))
        self.fp.flush()
        self.filelist.append(zinfo)
        self.NameToInfo[zinfo.filename] = zinfo

    def __del__(self):
        """Call the "close()" method in case the user forgot."""
        self.close()

    def close(self):
        """Close the file, and for mode "w" and "a" write the ending
        records."""
        if self.fp is None:
            return

        try:
            if self.mode in ("w", "a") and self._didModify: # write ending records
                pos1 = self.fp.tell()
                for zinfo in self.filelist:         # write central directory
                    dt = zinfo.date_time
                    dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
                    dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
                    extra = []
                    if zinfo.file_size > ZIP64_LIMIT \
                       or zinfo.compress_size > ZIP64_LIMIT:
                        extra.append(zinfo.file_size)
                        extra.append(zinfo.compress_size)
                        file_size = 0xffffffff
                        compress_size = 0xffffffff
                    else:
                        file_size = zinfo.file_size
                        compress_size = zinfo.compress_size

                    if zinfo.header_offset > ZIP64_LIMIT:
                        extra.append(zinfo.header_offset)
                        header_offset = 0xffffffff
                    else:
                        header_offset = zinfo.header_offset

                    extra_data = zinfo.extra
                    min_version = 0
                    if extra:
                        # Append a ZIP64 field to the extra's
                        extra_data = struct.pack(
                            '<HH' + 'Q'*len(extra),
                            1, 8*len(extra), *extra) + extra_data

                        min_version = ZIP64_VERSION

                    if zinfo.compress_type == ZIP_BZIP2:
                        min_version = max(BZIP2_VERSION, min_version)
                    elif zinfo.compress_type == ZIP_LZMA:
                        min_version = max(LZMA_VERSION, min_version)

                    extract_version = max(min_version, zinfo.extract_version)
                    create_version = max(min_version, zinfo.create_version)
                    try:
                        filename, flag_bits = zinfo._encodeFilenameFlags()
                        centdir = struct.pack(structCentralDir,
                                              stringCentralDir, create_version,
                                              zinfo.create_system, extract_version, zinfo.reserved,
                                              flag_bits, zinfo.compress_type, dostime, dosdate,
                                              zinfo.CRC, compress_size, file_size,
                                              len(filename), len(extra_data), len(zinfo.comment),
                                              0, zinfo.internal_attr, zinfo.external_attr,
                                              header_offset)
                    except DeprecationWarning:
                        print((structCentralDir, stringCentralDir, create_version,
                               zinfo.create_system, extract_version, zinfo.reserved,
                               zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
                               zinfo.CRC, compress_size, file_size,
                               len(zinfo.filename), len(extra_data), len(zinfo.comment),
                               0, zinfo.internal_attr, zinfo.external_attr,
                               header_offset), file=sys.stderr)
                        raise
                    self.fp.write(centdir)
                    self.fp.write(filename)
                    self.fp.write(extra_data)
                    self.fp.write(zinfo.comment)

                pos2 = self.fp.tell()
                # Write end-of-zip-archive record
                centDirCount = len(self.filelist)
                centDirSize = pos2 - pos1
                centDirOffset = pos1
                requires_zip64 = None
                if centDirCount > ZIP_FILECOUNT_LIMIT:
                    requires_zip64 = "Files count"
                elif centDirOffset > ZIP64_LIMIT:
                    requires_zip64 = "Central directory offset"
                elif centDirSize > ZIP64_LIMIT:
                    requires_zip64 = "Central directory size"
                if requires_zip64:
                    # Need to write the ZIP64 end-of-archive records
                    if not self._allowZip64:
                        raise LargeZipFile(requires_zip64 +
                                           " would require ZIP64 extensions")
                    zip64endrec = struct.pack(
                        structEndArchive64, stringEndArchive64,
                        44, 45, 45, 0, 0, centDirCount, centDirCount,
                        centDirSize, centDirOffset)
                    self.fp.write(zip64endrec)

                    zip64locrec = struct.pack(
                        structEndArchive64Locator,
                        stringEndArchive64Locator, 0, pos2, 1)
                    self.fp.write(zip64locrec)
                    centDirCount = min(centDirCount, 0xFFFF)
                    centDirSize = min(centDirSize, 0xFFFFFFFF)
                    centDirOffset = min(centDirOffset, 0xFFFFFFFF)

                endrec = struct.pack(structEndArchive, stringEndArchive,
                                     0, 0, centDirCount, centDirCount,
                                     centDirSize, centDirOffset, len(self._comment))
                self.fp.write(endrec)
                self.fp.write(self._comment)
                self.fp.flush()
        finally:
            fp = self.fp
            self.fp = None
            if not self._filePassed:
                fp.close()


class PyZipFile(ZipFile):
    """Class to create ZIP archives with Python library files and packages."""

    def __init__(self, file, mode="r", compression=ZIP_STORED,
                 allowZip64=True, optimize=-1):
        ZipFile.__init__(self, file, mode=mode, compression=compression,
                         allowZip64=allowZip64)
        self._optimize = optimize

    def writepy(self, pathname, basename="", filterfunc=None):
        """Add all files from "pathname" to the ZIP archive.

        If pathname is a package directory, search the directory and
        all package subdirectories recursively for all *.py and enter
        the modules into the archive.  If pathname is a plain
        directory, listdir *.py and enter all modules.  Else, pathname
        must be a Python *.py file and the module will be put into the
        archive.  Added modules are always module.pyo or module.pyc.
        This method will compile the module.py into module.pyc if
        necessary.
        If filterfunc(pathname) is given, it is called with every argument.
        When it is False, the file or directory is skipped.
        """
        if filterfunc and not filterfunc(pathname):
            if self.debug:
                label = 'path' if os.path.isdir(pathname) else 'file'
                print('%s "%s" skipped by filterfunc' % (label, pathname))
            return
        dir, name = os.path.split(pathname)
        if os.path.isdir(pathname):
            initname = os.path.join(pathname, "__init__.py")
            if os.path.isfile(initname):
                # This is a package directory, add it
                if basename:
                    basename = "%s/%s" % (basename, name)
                else:
                    basename = name
                if self.debug:
                    print("Adding package in", pathname, "as", basename)
                fname, arcname = self._get_codename(initname[0:-3], basename)
                if self.debug:
                    print("Adding", arcname)
                self.write(fname, arcname)
                dirlist = os.listdir(pathname)
                dirlist.remove("__init__.py")
                # Add all *.py files and package subdirectories
                for filename in dirlist:
                    path = os.path.join(pathname, filename)
                    root, ext = os.path.splitext(filename)
                    if os.path.isdir(path):
                        if os.path.isfile(os.path.join(path, "__init__.py")):
                            # This is a package directory, add it
                            self.writepy(path, basename,
                                         filterfunc=filterfunc)  # Recursive call
                    elif ext == ".py":
                        if filterfunc and not filterfunc(path):
                            if self.debug:
                                print('file "%s" skipped by filterfunc' % path)
                            continue
                        fname, arcname = self._get_codename(path[0:-3],
                                                            basename)
                        if self.debug:
                            print("Adding", arcname)
                        self.write(fname, arcname)
            else:
                # This is NOT a package directory, add its files at top level
                if self.debug:
                    print("Adding files from directory", pathname)
                for filename in os.listdir(pathname):
                    path = os.path.join(pathname, filename)
                    root, ext = os.path.splitext(filename)
                    if ext == ".py":
                        if filterfunc and not filterfunc(path):
                            if self.debug:
                                print('file "%s" skipped by filterfunc' % path)
                            continue
                        fname, arcname = self._get_codename(path[0:-3],
                                                            basename)
                        if self.debug:
                            print("Adding", arcname)
                        self.write(fname, arcname)
        else:
            if pathname[-3:] != ".py":
                raise RuntimeError(
                    'Files added with writepy() must end with ".py"')
            fname, arcname = self._get_codename(pathname[0:-3], basename)
            if self.debug:
                print("Adding file", arcname)
            self.write(fname, arcname)

    def _get_codename(self, pathname, basename):
        """Return (filename, archivename) for the path.

        Given a module name path, return the correct file path and
        archive name, compiling if necessary.  For example, given
        /python/lib/string, return (/python/lib/string.pyc, string).
        """
        def _compile(file, optimize=-1):
            import py_compile
            if self.debug:
                print("Compiling", file)
            try:
                py_compile.compile(file, doraise=True, optimize=optimize)
            except py_compile.PyCompileError as err:
                print(err.msg)
                return False
            return True

        file_py  = pathname + ".py"
        file_pyc = pathname + ".pyc"
        file_pyo = pathname + ".pyo"
        pycache_pyc = importlib.util.cache_from_source(file_py, True)
        pycache_pyo = importlib.util.cache_from_source(file_py, False)
        if self._optimize == -1:
            # legacy mode: use whatever file is present
            if (os.path.isfile(file_pyo) and
                os.stat(file_pyo).st_mtime >= os.stat(file_py).st_mtime):
                # Use .pyo file.
                arcname = fname = file_pyo
            elif (os.path.isfile(file_pyc) and
                  os.stat(file_pyc).st_mtime >= os.stat(file_py).st_mtime):
                # Use .pyc file.
                arcname = fname = file_pyc
            elif (os.path.isfile(pycache_pyc) and
                  os.stat(pycache_pyc).st_mtime >= os.stat(file_py).st_mtime):
                # Use the __pycache__/*.pyc file, but write it to the legacy pyc
                # file name in the archive.
                fname = pycache_pyc
                arcname = file_pyc
            elif (os.path.isfile(pycache_pyo) and
                  os.stat(pycache_pyo).st_mtime >= os.stat(file_py).st_mtime):
                # Use the __pycache__/*.pyo file, but write it to the legacy pyo
                # file name in the archive.
                fname = pycache_pyo
                arcname = file_pyo
            else:
                # Compile py into PEP 3147 pyc file.
                if _compile(file_py):
                    fname = (pycache_pyc if __debug__ else pycache_pyo)
                    arcname = (file_pyc if __debug__ else file_pyo)
                else:
                    fname = arcname = file_py
        else:
            # new mode: use given optimization level
            if self._optimize == 0:
                fname = pycache_pyc
                arcname = file_pyc
            else:
                fname = pycache_pyo
                arcname = file_pyo
            if not (os.path.isfile(fname) and
                    os.stat(fname).st_mtime >= os.stat(file_py).st_mtime):
                if not _compile(file_py, optimize=self._optimize):
                    fname = arcname = file_py
        archivename = os.path.split(arcname)[1]
        if basename:
            archivename = "%s/%s" % (basename, archivename)
        return (fname, archivename)


def main(args = None):
    import textwrap
    USAGE=textwrap.dedent("""\
        Usage:
            zipfile.py -l zipfile.zip        # Show listing of a zipfile
            zipfile.py -t zipfile.zip        # Test if a zipfile is valid
            zipfile.py -e zipfile.zip target # Extract zipfile into target dir
            zipfile.py -c zipfile.zip src ... # Create zipfile from sources
        """)
    if args is None:
        args = sys.argv[1:]

    if not args or args[0] not in ('-l', '-c', '-e', '-t'):
        print(USAGE)
        sys.exit(1)

    if args[0] == '-l':
        if len(args) != 2:
            print(USAGE)
            sys.exit(1)
        with ZipFile(args[1], 'r') as zf:
            zf.printdir()

    elif args[0] == '-t':
        if len(args) != 2:
            print(USAGE)
            sys.exit(1)
        with ZipFile(args[1], 'r') as zf:
            badfile = zf.testzip()
        if badfile:
            print("The following enclosed file is corrupted: {!r}".format(badfile))
        print("Done testing")

    elif args[0] == '-e':
        if len(args) != 3:
            print(USAGE)
            sys.exit(1)

        with ZipFile(args[1], 'r') as zf:
            zf.extractall(args[2])

    elif args[0] == '-c':
        if len(args) < 3:
            print(USAGE)
            sys.exit(1)

        def addToZip(zf, path, zippath):
            if os.path.isfile(path):
                zf.write(path, zippath, ZIP_DEFLATED)
            elif os.path.isdir(path):
                if zippath:
                    zf.write(path, zippath)
                for nm in os.listdir(path):
                    addToZip(zf,
                             os.path.join(path, nm), os.path.join(zippath, nm))
            # else: ignore

        with ZipFile(args[1], 'w') as zf:
            for path in args[2:]:
                zippath = os.path.basename(path)
                if not zippath:
                    zippath = os.path.basename(os.path.dirname(path))
                if zippath in ('', os.curdir, os.pardir):
                    zippath = ''
                addToZip(zf, path, zippath)

if __name__ == "__main__":
    main()