| """A collection of string constants. |
| |
| Public module variables: |
| |
| whitespace -- a string containing all characters considered whitespace |
| lowercase -- a string containing all characters considered lowercase letters |
| uppercase -- a string containing all characters considered uppercase letters |
| letters -- a string containing all characters considered letters |
| digits -- a string containing all characters considered decimal digits |
| hexdigits -- a string containing all characters considered hexadecimal digits |
| octdigits -- a string containing all characters considered octal digits |
| punctuation -- a string containing all characters considered punctuation |
| printable -- a string containing all characters considered printable |
| |
| """ |
| |
| # Some strings for ctype-style character classification |
| whitespace = ' \t\n\r\v\f' |
| ascii_lowercase = 'abcdefghijklmnopqrstuvwxyz' |
| ascii_uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' |
| ascii_letters = ascii_lowercase + ascii_uppercase |
| digits = '0123456789' |
| hexdigits = digits + 'abcdef' + 'ABCDEF' |
| octdigits = '01234567' |
| punctuation = """!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~""" |
| printable = digits + ascii_letters + punctuation + whitespace |
| |
| # Functions which aren't available as string methods. |
| |
| # Capitalize the words in a string, e.g. " aBc dEf " -> "Abc Def". |
| def capwords(s, sep=None): |
| """capwords(s, [sep]) -> string |
| |
| Split the argument into words using split, capitalize each |
| word using capitalize, and join the capitalized words using |
| join. Note that this replaces runs of whitespace characters by |
| a single space. |
| |
| """ |
| return (sep or ' ').join([x.capitalize() for x in s.split(sep)]) |
| |
| |
| # Construct a translation map for bytes.translate |
| def maketrans(frm: bytes, to: bytes) -> bytes: |
| """maketrans(frm, to) -> bytes |
| |
| Return a translation table (a bytes object of length 256) |
| suitable for use in bytes.translate where each byte in frm is |
| mapped to the byte at the same position in to. |
| The strings frm and to must be of the same length. |
| """ |
| if len(frm) != len(to): |
| raise ValueError("maketrans arguments must have same length") |
| if not (isinstance(frm, bytes) and isinstance(to, bytes)): |
| raise TypeError("maketrans arguments must be bytes objects") |
| L = bytearray(range(256)) |
| for i, c in enumerate(frm): |
| L[c] = to[i] |
| return bytes(L) |
| |
| |
| #################################################################### |
| import re as _re |
| |
| class _multimap: |
| """Helper class for combining multiple mappings. |
| |
| Used by .{safe_,}substitute() to combine the mapping and keyword |
| arguments. |
| """ |
| def __init__(self, primary, secondary): |
| self._primary = primary |
| self._secondary = secondary |
| |
| def __getitem__(self, key): |
| try: |
| return self._primary[key] |
| except KeyError: |
| return self._secondary[key] |
| |
| |
| class _TemplateMetaclass(type): |
| pattern = r""" |
| %(delim)s(?: |
| (?P<escaped>%(delim)s) | # Escape sequence of two delimiters |
| (?P<named>%(id)s) | # delimiter and a Python identifier |
| {(?P<braced>%(id)s)} | # delimiter and a braced identifier |
| (?P<invalid>) # Other ill-formed delimiter exprs |
| ) |
| """ |
| |
| def __init__(cls, name, bases, dct): |
| super(_TemplateMetaclass, cls).__init__(name, bases, dct) |
| if 'pattern' in dct: |
| pattern = cls.pattern |
| else: |
| pattern = _TemplateMetaclass.pattern % { |
| 'delim' : _re.escape(cls.delimiter), |
| 'id' : cls.idpattern, |
| } |
| cls.pattern = _re.compile(pattern, _re.IGNORECASE | _re.VERBOSE) |
| |
| |
| class Template(metaclass=_TemplateMetaclass): |
| """A string class for supporting $-substitutions.""" |
| |
| delimiter = '$' |
| idpattern = r'[_a-z][_a-z0-9]*' |
| |
| def __init__(self, template): |
| self.template = template |
| |
| # Search for $$, $identifier, ${identifier}, and any bare $'s |
| |
| def _invalid(self, mo): |
| i = mo.start('invalid') |
| lines = self.template[:i].splitlines(True) |
| if not lines: |
| colno = 1 |
| lineno = 1 |
| else: |
| colno = i - len(''.join(lines[:-1])) |
| lineno = len(lines) |
| raise ValueError('Invalid placeholder in string: line %d, col %d' % |
| (lineno, colno)) |
| |
| def substitute(self, *args, **kws): |
| if len(args) > 1: |
| raise TypeError('Too many positional arguments') |
| if not args: |
| mapping = kws |
| elif kws: |
| mapping = _multimap(kws, args[0]) |
| else: |
| mapping = args[0] |
| # Helper function for .sub() |
| def convert(mo): |
| # Check the most common path first. |
| named = mo.group('named') or mo.group('braced') |
| if named is not None: |
| val = mapping[named] |
| # We use this idiom instead of str() because the latter will |
| # fail if val is a Unicode containing non-ASCII characters. |
| return '%s' % (val,) |
| if mo.group('escaped') is not None: |
| return self.delimiter |
| if mo.group('invalid') is not None: |
| self._invalid(mo) |
| raise ValueError('Unrecognized named group in pattern', |
| self.pattern) |
| return self.pattern.sub(convert, self.template) |
| |
| def safe_substitute(self, *args, **kws): |
| if len(args) > 1: |
| raise TypeError('Too many positional arguments') |
| if not args: |
| mapping = kws |
| elif kws: |
| mapping = _multimap(kws, args[0]) |
| else: |
| mapping = args[0] |
| # Helper function for .sub() |
| def convert(mo): |
| named = mo.group('named') |
| if named is not None: |
| try: |
| # We use this idiom instead of str() because the latter |
| # will fail if val is a Unicode containing non-ASCII |
| return '%s' % (mapping[named],) |
| except KeyError: |
| return self.delimiter + named |
| braced = mo.group('braced') |
| if braced is not None: |
| try: |
| return '%s' % (mapping[braced],) |
| except KeyError: |
| return self.delimiter + '{' + braced + '}' |
| if mo.group('escaped') is not None: |
| return self.delimiter |
| if mo.group('invalid') is not None: |
| return self.delimiter |
| raise ValueError('Unrecognized named group in pattern', |
| self.pattern) |
| return self.pattern.sub(convert, self.template) |
| |
| |
| |
| ######################################################################## |
| # the Formatter class |
| # see PEP 3101 for details and purpose of this class |
| |
| # The hard parts are reused from the C implementation. They're |
| # exposed here via the sys module. sys was chosen because it's always |
| # available and doesn't have to be dynamically loaded. |
| |
| # The overall parser is implemented in str._formatter_parser. |
| # The field name parser is implemented in str._formatter_field_name_split |
| |
| class Formatter: |
| def format(self, format_string, *args, **kwargs): |
| return self.vformat(format_string, args, kwargs) |
| |
| def vformat(self, format_string, args, kwargs): |
| used_args = set() |
| result = self._vformat(format_string, args, kwargs, used_args, 2) |
| self.check_unused_args(used_args, args, kwargs) |
| return result |
| |
| def _vformat(self, format_string, args, kwargs, used_args, recursion_depth): |
| if recursion_depth < 0: |
| raise ValueError('Max string recursion exceeded') |
| result = [] |
| for literal_text, field_name, format_spec, conversion in \ |
| self.parse(format_string): |
| |
| # output the literal text |
| if literal_text: |
| result.append(literal_text) |
| |
| # if there's a field, output it |
| if field_name is not None: |
| # this is some markup, find the object and do |
| # the formatting |
| |
| # given the field_name, find the object it references |
| # and the argument it came from |
| obj, arg_used = self.get_field(field_name, args, kwargs) |
| used_args.add(arg_used) |
| |
| # do any conversion on the resulting object |
| obj = self.convert_field(obj, conversion) |
| |
| # expand the format spec, if needed |
| format_spec = self._vformat(format_spec, args, kwargs, |
| used_args, recursion_depth-1) |
| |
| # format the object and append to the result |
| result.append(self.format_field(obj, format_spec)) |
| |
| return ''.join(result) |
| |
| |
| def get_value(self, key, args, kwargs): |
| if isinstance(key, int): |
| return args[key] |
| else: |
| return kwargs[key] |
| |
| |
| def check_unused_args(self, used_args, args, kwargs): |
| pass |
| |
| |
| def format_field(self, value, format_spec): |
| return format(value, format_spec) |
| |
| |
| def convert_field(self, value, conversion): |
| # do any conversion on the resulting object |
| if conversion == 'r': |
| return repr(value) |
| elif conversion == 's': |
| return str(value) |
| elif conversion is None: |
| return value |
| raise ValueError("Unknown converion specifier {0!s}".format(conversion)) |
| |
| |
| # returns an iterable that contains tuples of the form: |
| # (literal_text, field_name, format_spec, conversion) |
| # literal_text can be zero length |
| # field_name can be None, in which case there's no |
| # object to format and output |
| # if field_name is not None, it is looked up, formatted |
| # with format_spec and conversion and then used |
| def parse(self, format_string): |
| return format_string._formatter_parser() |
| |
| |
| # given a field_name, find the object it references. |
| # field_name: the field being looked up, e.g. "0.name" |
| # or "lookup[3]" |
| # used_args: a set of which args have been used |
| # args, kwargs: as passed in to vformat |
| def get_field(self, field_name, args, kwargs): |
| first, rest = field_name._formatter_field_name_split() |
| |
| obj = self.get_value(first, args, kwargs) |
| |
| # loop through the rest of the field_name, doing |
| # getattr or getitem as needed |
| for is_attr, i in rest: |
| if is_attr: |
| obj = getattr(obj, i) |
| else: |
| obj = obj[i] |
| |
| return obj, first |