| # Copyright (C) 2001-2007 Python Software Foundation |
| # Author: Barry Warsaw |
| # Contact: email-sig@python.org |
| |
| """Basic message object for the email package object model.""" |
| |
| __all__ = ['Message'] |
| |
| import re |
| import uu |
| import base64 |
| import binascii |
| import warnings |
| from io import BytesIO, StringIO |
| |
| # Intrapackage imports |
| from email import utils |
| from email import errors |
| from email import header |
| from email import charset as _charset |
| Charset = _charset.Charset |
| |
| SEMISPACE = '; ' |
| |
| # Regular expression that matches `special' characters in parameters, the |
| # existence of which force quoting of the parameter value. |
| tspecials = re.compile(r'[ \(\)<>@,;:\\"/\[\]\?=]') |
| |
| # How to figure out if we are processing strings that come from a byte |
| # source with undecodable characters. |
| _has_surrogates = re.compile( |
| '([^\ud800-\udbff]|\A)[\udc00-\udfff]([^\udc00-\udfff]|\Z)').search |
| |
| |
| # Helper functions |
| def _sanitize_header(name, value): |
| # If the header value contains surrogates, return a Header using |
| # the unknown-8bit charset to encode the bytes as encoded words. |
| if not isinstance(value, str): |
| # Assume it is already a header object |
| return value |
| if _has_surrogates(value): |
| return header.Header(value, charset=_charset.UNKNOWN8BIT, |
| header_name=name) |
| else: |
| return value |
| |
| def _splitparam(param): |
| # Split header parameters. BAW: this may be too simple. It isn't |
| # strictly RFC 2045 (section 5.1) compliant, but it catches most headers |
| # found in the wild. We may eventually need a full fledged parser |
| # eventually. |
| a, sep, b = param.partition(';') |
| if not sep: |
| return a.strip(), None |
| return a.strip(), b.strip() |
| |
| def _formatparam(param, value=None, quote=True): |
| """Convenience function to format and return a key=value pair. |
| |
| This will quote the value if needed or if quote is true. If value is a |
| three tuple (charset, language, value), it will be encoded according |
| to RFC2231 rules. If it contains non-ascii characters it will likewise |
| be encoded according to RFC2231 rules, using the utf-8 charset and |
| a null language. |
| """ |
| if value is not None and len(value) > 0: |
| # A tuple is used for RFC 2231 encoded parameter values where items |
| # are (charset, language, value). charset is a string, not a Charset |
| # instance. RFC 2231 encoded values are never quoted, per RFC. |
| if isinstance(value, tuple): |
| # Encode as per RFC 2231 |
| param += '*' |
| value = utils.encode_rfc2231(value[2], value[0], value[1]) |
| return '%s=%s' % (param, value) |
| else: |
| try: |
| value.encode('ascii') |
| except UnicodeEncodeError: |
| param += '*' |
| value = utils.encode_rfc2231(value, 'utf-8', '') |
| return '%s=%s' % (param, value) |
| # BAW: Please check this. I think that if quote is set it should |
| # force quoting even if not necessary. |
| if quote or tspecials.search(value): |
| return '%s="%s"' % (param, utils.quote(value)) |
| else: |
| return '%s=%s' % (param, value) |
| else: |
| return param |
| |
| def _parseparam(s): |
| plist = [] |
| while s[:1] == ';': |
| s = s[1:] |
| end = s.find(';') |
| while end > 0 and (s.count('"', 0, end) - s.count('\\"', 0, end)) % 2: |
| end = s.find(';', end + 1) |
| if end < 0: |
| end = len(s) |
| f = s[:end] |
| if '=' in f: |
| i = f.index('=') |
| f = f[:i].strip().lower() + '=' + f[i+1:].strip() |
| plist.append(f.strip()) |
| s = s[end:] |
| return plist |
| |
| |
| def _unquotevalue(value): |
| # This is different than utils.collapse_rfc2231_value() because it doesn't |
| # try to convert the value to a unicode. Message.get_param() and |
| # Message.get_params() are both currently defined to return the tuple in |
| # the face of RFC 2231 parameters. |
| if isinstance(value, tuple): |
| return value[0], value[1], utils.unquote(value[2]) |
| else: |
| return utils.unquote(value) |
| |
| |
| |
| class Message: |
| """Basic message object. |
| |
| A message object is defined as something that has a bunch of RFC 2822 |
| headers and a payload. It may optionally have an envelope header |
| (a.k.a. Unix-From or From_ header). If the message is a container (i.e. a |
| multipart or a message/rfc822), then the payload is a list of Message |
| objects, otherwise it is a string. |
| |
| Message objects implement part of the `mapping' interface, which assumes |
| there is exactly one occurrence of the header per message. Some headers |
| do in fact appear multiple times (e.g. Received) and for those headers, |
| you must use the explicit API to set or get all the headers. Not all of |
| the mapping methods are implemented. |
| """ |
| def __init__(self): |
| self._headers = [] |
| self._unixfrom = None |
| self._payload = None |
| self._charset = None |
| # Defaults for multipart messages |
| self.preamble = self.epilogue = None |
| self.defects = [] |
| # Default content type |
| self._default_type = 'text/plain' |
| |
| def __str__(self): |
| """Return the entire formatted message as a string. |
| This includes the headers, body, and envelope header. |
| """ |
| return self.as_string() |
| |
| def as_string(self, unixfrom=False, maxheaderlen=0): |
| """Return the entire formatted message as a string. |
| Optional `unixfrom' when True, means include the Unix From_ envelope |
| header. |
| |
| This is a convenience method and may not generate the message exactly |
| as you intend. For more flexibility, use the flatten() method of a |
| Generator instance. |
| """ |
| from email.generator import Generator |
| fp = StringIO() |
| g = Generator(fp, mangle_from_=False, maxheaderlen=maxheaderlen) |
| g.flatten(self, unixfrom=unixfrom) |
| return fp.getvalue() |
| |
| def is_multipart(self): |
| """Return True if the message consists of multiple parts.""" |
| return isinstance(self._payload, list) |
| |
| # |
| # Unix From_ line |
| # |
| def set_unixfrom(self, unixfrom): |
| self._unixfrom = unixfrom |
| |
| def get_unixfrom(self): |
| return self._unixfrom |
| |
| # |
| # Payload manipulation. |
| # |
| def attach(self, payload): |
| """Add the given payload to the current payload. |
| |
| The current payload will always be a list of objects after this method |
| is called. If you want to set the payload to a scalar object, use |
| set_payload() instead. |
| """ |
| if self._payload is None: |
| self._payload = [payload] |
| else: |
| self._payload.append(payload) |
| |
| def get_payload(self, i=None, decode=False): |
| """Return a reference to the payload. |
| |
| The payload will either be a list object or a string. If you mutate |
| the list object, you modify the message's payload in place. Optional |
| i returns that index into the payload. |
| |
| Optional decode is a flag indicating whether the payload should be |
| decoded or not, according to the Content-Transfer-Encoding header |
| (default is False). |
| |
| When True and the message is not a multipart, the payload will be |
| decoded if this header's value is `quoted-printable' or `base64'. If |
| some other encoding is used, or the header is missing, or if the |
| payload has bogus data (i.e. bogus base64 or uuencoded data), the |
| payload is returned as-is. |
| |
| If the message is a multipart and the decode flag is True, then None |
| is returned. |
| """ |
| # Here is the logic table for this code, based on the email5.0.0 code: |
| # i decode is_multipart result |
| # ------ ------ ------------ ------------------------------ |
| # None True True None |
| # i True True None |
| # None False True _payload (a list) |
| # i False True _payload element i (a Message) |
| # i False False error (not a list) |
| # i True False error (not a list) |
| # None False False _payload |
| # None True False _payload decoded (bytes) |
| # Note that Barry planned to factor out the 'decode' case, but that |
| # isn't so easy now that we handle the 8 bit data, which needs to be |
| # converted in both the decode and non-decode path. |
| if self.is_multipart(): |
| if decode: |
| return None |
| if i is None: |
| return self._payload |
| else: |
| return self._payload[i] |
| # For backward compatibility, Use isinstance and this error message |
| # instead of the more logical is_multipart test. |
| if i is not None and not isinstance(self._payload, list): |
| raise TypeError('Expected list, got %s' % type(self._payload)) |
| payload = self._payload |
| cte = self.get('content-transfer-encoding', '').lower() |
| # payload may be bytes here. |
| if isinstance(payload, str): |
| if _has_surrogates(payload): |
| bpayload = payload.encode('ascii', 'surrogateescape') |
| if not decode: |
| try: |
| payload = bpayload.decode(self.get_param('charset', 'ascii'), 'replace') |
| except LookupError: |
| payload = bpayload.decode('ascii', 'replace') |
| elif decode: |
| try: |
| bpayload = payload.encode('ascii') |
| except UnicodeError: |
| # This won't happen for RFC compliant messages (messages |
| # containing only ASCII codepoints in the unicode input). |
| # If it does happen, turn the string into bytes in a way |
| # guaranteed not to fail. |
| bpayload = payload.encode('raw-unicode-escape') |
| if not decode: |
| return payload |
| if cte == 'quoted-printable': |
| return utils._qdecode(bpayload) |
| elif cte == 'base64': |
| try: |
| return base64.b64decode(bpayload) |
| except binascii.Error: |
| # Incorrect padding |
| return bpayload |
| elif cte in ('x-uuencode', 'uuencode', 'uue', 'x-uue'): |
| in_file = BytesIO(bpayload) |
| out_file = BytesIO() |
| try: |
| uu.decode(in_file, out_file, quiet=True) |
| return out_file.getvalue() |
| except uu.Error: |
| # Some decoding problem |
| return bpayload |
| if isinstance(payload, str): |
| return bpayload |
| return payload |
| |
| def set_payload(self, payload, charset=None): |
| """Set the payload to the given value. |
| |
| Optional charset sets the message's default character set. See |
| set_charset() for details. |
| """ |
| self._payload = payload |
| if charset is not None: |
| self.set_charset(charset) |
| |
| def set_charset(self, charset): |
| """Set the charset of the payload to a given character set. |
| |
| charset can be a Charset instance, a string naming a character set, or |
| None. If it is a string it will be converted to a Charset instance. |
| If charset is None, the charset parameter will be removed from the |
| Content-Type field. Anything else will generate a TypeError. |
| |
| The message will be assumed to be of type text/* encoded with |
| charset.input_charset. It will be converted to charset.output_charset |
| and encoded properly, if needed, when generating the plain text |
| representation of the message. MIME headers (MIME-Version, |
| Content-Type, Content-Transfer-Encoding) will be added as needed. |
| """ |
| if charset is None: |
| self.del_param('charset') |
| self._charset = None |
| return |
| if not isinstance(charset, Charset): |
| charset = Charset(charset) |
| self._charset = charset |
| if 'MIME-Version' not in self: |
| self.add_header('MIME-Version', '1.0') |
| if 'Content-Type' not in self: |
| self.add_header('Content-Type', 'text/plain', |
| charset=charset.get_output_charset()) |
| else: |
| self.set_param('charset', charset.get_output_charset()) |
| if charset != charset.get_output_charset(): |
| self._payload = charset.body_encode(self._payload) |
| if 'Content-Transfer-Encoding' not in self: |
| cte = charset.get_body_encoding() |
| try: |
| cte(self) |
| except TypeError: |
| self._payload = charset.body_encode(self._payload) |
| self.add_header('Content-Transfer-Encoding', cte) |
| |
| def get_charset(self): |
| """Return the Charset instance associated with the message's payload. |
| """ |
| return self._charset |
| |
| # |
| # MAPPING INTERFACE (partial) |
| # |
| def __len__(self): |
| """Return the total number of headers, including duplicates.""" |
| return len(self._headers) |
| |
| def __getitem__(self, name): |
| """Get a header value. |
| |
| Return None if the header is missing instead of raising an exception. |
| |
| Note that if the header appeared multiple times, exactly which |
| occurrence gets returned is undefined. Use get_all() to get all |
| the values matching a header field name. |
| """ |
| return self.get(name) |
| |
| def __setitem__(self, name, val): |
| """Set the value of a header. |
| |
| Note: this does not overwrite an existing header with the same field |
| name. Use __delitem__() first to delete any existing headers. |
| """ |
| self._headers.append((name, val)) |
| |
| def __delitem__(self, name): |
| """Delete all occurrences of a header, if present. |
| |
| Does not raise an exception if the header is missing. |
| """ |
| name = name.lower() |
| newheaders = [] |
| for k, v in self._headers: |
| if k.lower() != name: |
| newheaders.append((k, v)) |
| self._headers = newheaders |
| |
| def __contains__(self, name): |
| return name.lower() in [k.lower() for k, v in self._headers] |
| |
| def __iter__(self): |
| for field, value in self._headers: |
| yield field |
| |
| def keys(self): |
| """Return a list of all the message's header field names. |
| |
| These will be sorted in the order they appeared in the original |
| message, or were added to the message, and may contain duplicates. |
| Any fields deleted and re-inserted are always appended to the header |
| list. |
| """ |
| return [k for k, v in self._headers] |
| |
| def values(self): |
| """Return a list of all the message's header values. |
| |
| These will be sorted in the order they appeared in the original |
| message, or were added to the message, and may contain duplicates. |
| Any fields deleted and re-inserted are always appended to the header |
| list. |
| """ |
| return [_sanitize_header(k, v) for k, v in self._headers] |
| |
| def items(self): |
| """Get all the message's header fields and values. |
| |
| These will be sorted in the order they appeared in the original |
| message, or were added to the message, and may contain duplicates. |
| Any fields deleted and re-inserted are always appended to the header |
| list. |
| """ |
| return [(k, _sanitize_header(k, v)) for k, v in self._headers] |
| |
| def get(self, name, failobj=None): |
| """Get a header value. |
| |
| Like __getitem__() but return failobj instead of None when the field |
| is missing. |
| """ |
| name = name.lower() |
| for k, v in self._headers: |
| if k.lower() == name: |
| return _sanitize_header(k, v) |
| return failobj |
| |
| # |
| # Additional useful stuff |
| # |
| |
| def get_all(self, name, failobj=None): |
| """Return a list of all the values for the named field. |
| |
| These will be sorted in the order they appeared in the original |
| message, and may contain duplicates. Any fields deleted and |
| re-inserted are always appended to the header list. |
| |
| If no such fields exist, failobj is returned (defaults to None). |
| """ |
| values = [] |
| name = name.lower() |
| for k, v in self._headers: |
| if k.lower() == name: |
| values.append(_sanitize_header(k, v)) |
| if not values: |
| return failobj |
| return values |
| |
| def add_header(self, _name, _value, **_params): |
| """Extended header setting. |
| |
| name is the header field to add. keyword arguments can be used to set |
| additional parameters for the header field, with underscores converted |
| to dashes. Normally the parameter will be added as key="value" unless |
| value is None, in which case only the key will be added. If a |
| parameter value contains non-ASCII characters it can be specified as a |
| three-tuple of (charset, language, value), in which case it will be |
| encoded according to RFC2231 rules. Otherwise it will be encoded using |
| the utf-8 charset and a language of ''. |
| |
| Examples: |
| |
| msg.add_header('content-disposition', 'attachment', filename='bud.gif') |
| msg.add_header('content-disposition', 'attachment', |
| filename=('utf-8', '', Fußballer.ppt')) |
| msg.add_header('content-disposition', 'attachment', |
| filename='Fußballer.ppt')) |
| """ |
| parts = [] |
| for k, v in _params.items(): |
| if v is None: |
| parts.append(k.replace('_', '-')) |
| else: |
| parts.append(_formatparam(k.replace('_', '-'), v)) |
| if _value is not None: |
| parts.insert(0, _value) |
| self._headers.append((_name, SEMISPACE.join(parts))) |
| |
| def replace_header(self, _name, _value): |
| """Replace a header. |
| |
| Replace the first matching header found in the message, retaining |
| header order and case. If no matching header was found, a KeyError is |
| raised. |
| """ |
| _name = _name.lower() |
| for i, (k, v) in zip(range(len(self._headers)), self._headers): |
| if k.lower() == _name: |
| self._headers[i] = (k, _value) |
| break |
| else: |
| raise KeyError(_name) |
| |
| # |
| # Use these three methods instead of the three above. |
| # |
| |
| def get_content_type(self): |
| """Return the message's content type. |
| |
| The returned string is coerced to lower case of the form |
| `maintype/subtype'. If there was no Content-Type header in the |
| message, the default type as given by get_default_type() will be |
| returned. Since according to RFC 2045, messages always have a default |
| type this will always return a value. |
| |
| RFC 2045 defines a message's default type to be text/plain unless it |
| appears inside a multipart/digest container, in which case it would be |
| message/rfc822. |
| """ |
| missing = object() |
| value = self.get('content-type', missing) |
| if value is missing: |
| # This should have no parameters |
| return self.get_default_type() |
| ctype = _splitparam(value)[0].lower() |
| # RFC 2045, section 5.2 says if its invalid, use text/plain |
| if ctype.count('/') != 1: |
| return 'text/plain' |
| return ctype |
| |
| def get_content_maintype(self): |
| """Return the message's main content type. |
| |
| This is the `maintype' part of the string returned by |
| get_content_type(). |
| """ |
| ctype = self.get_content_type() |
| return ctype.split('/')[0] |
| |
| def get_content_subtype(self): |
| """Returns the message's sub-content type. |
| |
| This is the `subtype' part of the string returned by |
| get_content_type(). |
| """ |
| ctype = self.get_content_type() |
| return ctype.split('/')[1] |
| |
| def get_default_type(self): |
| """Return the `default' content type. |
| |
| Most messages have a default content type of text/plain, except for |
| messages that are subparts of multipart/digest containers. Such |
| subparts have a default content type of message/rfc822. |
| """ |
| return self._default_type |
| |
| def set_default_type(self, ctype): |
| """Set the `default' content type. |
| |
| ctype should be either "text/plain" or "message/rfc822", although this |
| is not enforced. The default content type is not stored in the |
| Content-Type header. |
| """ |
| self._default_type = ctype |
| |
| def _get_params_preserve(self, failobj, header): |
| # Like get_params() but preserves the quoting of values. BAW: |
| # should this be part of the public interface? |
| missing = object() |
| value = self.get(header, missing) |
| if value is missing: |
| return failobj |
| params = [] |
| for p in _parseparam(';' + value): |
| try: |
| name, val = p.split('=', 1) |
| name = name.strip() |
| val = val.strip() |
| except ValueError: |
| # Must have been a bare attribute |
| name = p.strip() |
| val = '' |
| params.append((name, val)) |
| params = utils.decode_params(params) |
| return params |
| |
| def get_params(self, failobj=None, header='content-type', unquote=True): |
| """Return the message's Content-Type parameters, as a list. |
| |
| The elements of the returned list are 2-tuples of key/value pairs, as |
| split on the `=' sign. The left hand side of the `=' is the key, |
| while the right hand side is the value. If there is no `=' sign in |
| the parameter the value is the empty string. The value is as |
| described in the get_param() method. |
| |
| Optional failobj is the object to return if there is no Content-Type |
| header. Optional header is the header to search instead of |
| Content-Type. If unquote is True, the value is unquoted. |
| """ |
| missing = object() |
| params = self._get_params_preserve(missing, header) |
| if params is missing: |
| return failobj |
| if unquote: |
| return [(k, _unquotevalue(v)) for k, v in params] |
| else: |
| return params |
| |
| def get_param(self, param, failobj=None, header='content-type', |
| unquote=True): |
| """Return the parameter value if found in the Content-Type header. |
| |
| Optional failobj is the object to return if there is no Content-Type |
| header, or the Content-Type header has no such parameter. Optional |
| header is the header to search instead of Content-Type. |
| |
| Parameter keys are always compared case insensitively. The return |
| value can either be a string, or a 3-tuple if the parameter was RFC |
| 2231 encoded. When it's a 3-tuple, the elements of the value are of |
| the form (CHARSET, LANGUAGE, VALUE). Note that both CHARSET and |
| LANGUAGE can be None, in which case you should consider VALUE to be |
| encoded in the us-ascii charset. You can usually ignore LANGUAGE. |
| |
| Your application should be prepared to deal with 3-tuple return |
| values, and can convert the parameter to a Unicode string like so: |
| |
| param = msg.get_param('foo') |
| if isinstance(param, tuple): |
| param = unicode(param[2], param[0] or 'us-ascii') |
| |
| In any case, the parameter value (either the returned string, or the |
| VALUE item in the 3-tuple) is always unquoted, unless unquote is set |
| to False. |
| """ |
| if header not in self: |
| return failobj |
| for k, v in self._get_params_preserve(failobj, header): |
| if k.lower() == param.lower(): |
| if unquote: |
| return _unquotevalue(v) |
| else: |
| return v |
| return failobj |
| |
| def set_param(self, param, value, header='Content-Type', requote=True, |
| charset=None, language=''): |
| """Set a parameter in the Content-Type header. |
| |
| If the parameter already exists in the header, its value will be |
| replaced with the new value. |
| |
| If header is Content-Type and has not yet been defined for this |
| message, it will be set to "text/plain" and the new parameter and |
| value will be appended as per RFC 2045. |
| |
| An alternate header can specified in the header argument, and all |
| parameters will be quoted as necessary unless requote is False. |
| |
| If charset is specified, the parameter will be encoded according to RFC |
| 2231. Optional language specifies the RFC 2231 language, defaulting |
| to the empty string. Both charset and language should be strings. |
| """ |
| if not isinstance(value, tuple) and charset: |
| value = (charset, language, value) |
| |
| if header not in self and header.lower() == 'content-type': |
| ctype = 'text/plain' |
| else: |
| ctype = self.get(header) |
| if not self.get_param(param, header=header): |
| if not ctype: |
| ctype = _formatparam(param, value, requote) |
| else: |
| ctype = SEMISPACE.join( |
| [ctype, _formatparam(param, value, requote)]) |
| else: |
| ctype = '' |
| for old_param, old_value in self.get_params(header=header, |
| unquote=requote): |
| append_param = '' |
| if old_param.lower() == param.lower(): |
| append_param = _formatparam(param, value, requote) |
| else: |
| append_param = _formatparam(old_param, old_value, requote) |
| if not ctype: |
| ctype = append_param |
| else: |
| ctype = SEMISPACE.join([ctype, append_param]) |
| if ctype != self.get(header): |
| del self[header] |
| self[header] = ctype |
| |
| def del_param(self, param, header='content-type', requote=True): |
| """Remove the given parameter completely from the Content-Type header. |
| |
| The header will be re-written in place without the parameter or its |
| value. All values will be quoted as necessary unless requote is |
| False. Optional header specifies an alternative to the Content-Type |
| header. |
| """ |
| if header not in self: |
| return |
| new_ctype = '' |
| for p, v in self.get_params(header=header, unquote=requote): |
| if p.lower() != param.lower(): |
| if not new_ctype: |
| new_ctype = _formatparam(p, v, requote) |
| else: |
| new_ctype = SEMISPACE.join([new_ctype, |
| _formatparam(p, v, requote)]) |
| if new_ctype != self.get(header): |
| del self[header] |
| self[header] = new_ctype |
| |
| def set_type(self, type, header='Content-Type', requote=True): |
| """Set the main type and subtype for the Content-Type header. |
| |
| type must be a string in the form "maintype/subtype", otherwise a |
| ValueError is raised. |
| |
| This method replaces the Content-Type header, keeping all the |
| parameters in place. If requote is False, this leaves the existing |
| header's quoting as is. Otherwise, the parameters will be quoted (the |
| default). |
| |
| An alternative header can be specified in the header argument. When |
| the Content-Type header is set, we'll always also add a MIME-Version |
| header. |
| """ |
| # BAW: should we be strict? |
| if not type.count('/') == 1: |
| raise ValueError |
| # Set the Content-Type, you get a MIME-Version |
| if header.lower() == 'content-type': |
| del self['mime-version'] |
| self['MIME-Version'] = '1.0' |
| if header not in self: |
| self[header] = type |
| return |
| params = self.get_params(header=header, unquote=requote) |
| del self[header] |
| self[header] = type |
| # Skip the first param; it's the old type. |
| for p, v in params[1:]: |
| self.set_param(p, v, header, requote) |
| |
| def get_filename(self, failobj=None): |
| """Return the filename associated with the payload if present. |
| |
| The filename is extracted from the Content-Disposition header's |
| `filename' parameter, and it is unquoted. If that header is missing |
| the `filename' parameter, this method falls back to looking for the |
| `name' parameter. |
| """ |
| missing = object() |
| filename = self.get_param('filename', missing, 'content-disposition') |
| if filename is missing: |
| filename = self.get_param('name', missing, 'content-type') |
| if filename is missing: |
| return failobj |
| return utils.collapse_rfc2231_value(filename).strip() |
| |
| def get_boundary(self, failobj=None): |
| """Return the boundary associated with the payload if present. |
| |
| The boundary is extracted from the Content-Type header's `boundary' |
| parameter, and it is unquoted. |
| """ |
| missing = object() |
| boundary = self.get_param('boundary', missing) |
| if boundary is missing: |
| return failobj |
| # RFC 2046 says that boundaries may begin but not end in w/s |
| return utils.collapse_rfc2231_value(boundary).rstrip() |
| |
| def set_boundary(self, boundary): |
| """Set the boundary parameter in Content-Type to 'boundary'. |
| |
| This is subtly different than deleting the Content-Type header and |
| adding a new one with a new boundary parameter via add_header(). The |
| main difference is that using the set_boundary() method preserves the |
| order of the Content-Type header in the original message. |
| |
| HeaderParseError is raised if the message has no Content-Type header. |
| """ |
| missing = object() |
| params = self._get_params_preserve(missing, 'content-type') |
| if params is missing: |
| # There was no Content-Type header, and we don't know what type |
| # to set it to, so raise an exception. |
| raise errors.HeaderParseError('No Content-Type header found') |
| newparams = [] |
| foundp = False |
| for pk, pv in params: |
| if pk.lower() == 'boundary': |
| newparams.append(('boundary', '"%s"' % boundary)) |
| foundp = True |
| else: |
| newparams.append((pk, pv)) |
| if not foundp: |
| # The original Content-Type header had no boundary attribute. |
| # Tack one on the end. BAW: should we raise an exception |
| # instead??? |
| newparams.append(('boundary', '"%s"' % boundary)) |
| # Replace the existing Content-Type header with the new value |
| newheaders = [] |
| for h, v in self._headers: |
| if h.lower() == 'content-type': |
| parts = [] |
| for k, v in newparams: |
| if v == '': |
| parts.append(k) |
| else: |
| parts.append('%s=%s' % (k, v)) |
| newheaders.append((h, SEMISPACE.join(parts))) |
| |
| else: |
| newheaders.append((h, v)) |
| self._headers = newheaders |
| |
| def get_content_charset(self, failobj=None): |
| """Return the charset parameter of the Content-Type header. |
| |
| The returned string is always coerced to lower case. If there is no |
| Content-Type header, or if that header has no charset parameter, |
| failobj is returned. |
| """ |
| missing = object() |
| charset = self.get_param('charset', missing) |
| if charset is missing: |
| return failobj |
| if isinstance(charset, tuple): |
| # RFC 2231 encoded, so decode it, and it better end up as ascii. |
| pcharset = charset[0] or 'us-ascii' |
| try: |
| # LookupError will be raised if the charset isn't known to |
| # Python. UnicodeError will be raised if the encoded text |
| # contains a character not in the charset. |
| as_bytes = charset[2].encode('raw-unicode-escape') |
| charset = str(as_bytes, pcharset) |
| except (LookupError, UnicodeError): |
| charset = charset[2] |
| # charset characters must be in us-ascii range |
| try: |
| charset.encode('us-ascii') |
| except UnicodeError: |
| return failobj |
| # RFC 2046, $4.1.2 says charsets are not case sensitive |
| return charset.lower() |
| |
| def get_charsets(self, failobj=None): |
| """Return a list containing the charset(s) used in this message. |
| |
| The returned list of items describes the Content-Type headers' |
| charset parameter for this message and all the subparts in its |
| payload. |
| |
| Each item will either be a string (the value of the charset parameter |
| in the Content-Type header of that part) or the value of the |
| 'failobj' parameter (defaults to None), if the part does not have a |
| main MIME type of "text", or the charset is not defined. |
| |
| The list will contain one string for each part of the message, plus |
| one for the container message (i.e. self), so that a non-multipart |
| message will still return a list of length 1. |
| """ |
| return [part.get_content_charset(failobj) for part in self.walk()] |
| |
| # I.e. def walk(self): ... |
| from email.iterators import walk |