| # Copyright (C) 2001-2006 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 binascii | |
| import warnings | |
| from cStringIO import StringIO | |
| # Intrapackage imports | |
| import email.charset | |
| from email import utils | |
| from email import errors | |
| SEMISPACE = '; ' | |
| # Regular expression that matches `special' characters in parameters, the | |
| # existence of which force quoting of the parameter value. | |
| tspecials = re.compile(r'[ \(\)<>@,;:\\"/\[\]\?=]') | |
| # Helper functions | |
| 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 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. | |
| if isinstance(value, tuple): | |
| # Encode as per RFC 2231 | |
| param += '*' | |
| value = utils.encode_rfc2231(value[2], value[0], value[1]) | |
| # 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(unixfrom=True) | |
| def as_string(self, unixfrom=False): | |
| """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 because by default it mangles lines that begin with | |
| "From ". For more flexibility, use the flatten() method of a | |
| Generator instance. | |
| """ | |
| from email.generator import Generator | |
| fp = StringIO() | |
| g = Generator(fp) | |
| 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. | |
| """ | |
| if i is None: | |
| payload = self._payload | |
| elif not isinstance(self._payload, list): | |
| raise TypeError('Expected list, got %s' % type(self._payload)) | |
| else: | |
| payload = self._payload[i] | |
| if decode: | |
| if self.is_multipart(): | |
| return None | |
| cte = self.get('content-transfer-encoding', '').lower() | |
| if cte == 'quoted-printable': | |
| return utils._qdecode(payload) | |
| elif cte == 'base64': | |
| try: | |
| return utils._bdecode(payload) | |
| except binascii.Error: | |
| # Incorrect padding | |
| return payload | |
| elif cte in ('x-uuencode', 'uuencode', 'uue', 'x-uue'): | |
| sfp = StringIO() | |
| try: | |
| uu.decode(StringIO(payload+'\n'), sfp, quiet=True) | |
| payload = sfp.getvalue() | |
| except uu.Error: | |
| # Some decoding problem | |
| return payload | |
| # Everything else, including encodings with 8bit or 7bit are returned | |
| # unchanged. | |
| 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 isinstance(charset, basestring): | |
| charset = email.charset.Charset(charset) | |
| if not isinstance(charset, email.charset.Charset): | |
| raise TypeError(charset) | |
| # BAW: should we accept strings that can serve as arguments to the | |
| # Charset constructor? | |
| 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 isinstance(self._payload, unicode): | |
| self._payload = self._payload.encode(charset.output_charset) | |
| if str(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 has_key(self, name): | |
| """Return true if the message contains the header.""" | |
| missing = object() | |
| return self.get(name, missing) is not missing | |
| 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 [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 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 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(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 must be specified as a | |
| three-tuple of (charset, language, value), in which case it will be | |
| encoded according to RFC2231 rules. | |
| Example: | |
| msg.add_header('content-disposition', 'attachment', filename='bud.gif') | |
| """ | |
| 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. | |
| charset = unicode(charset[2], pcharset).encode('us-ascii') | |
| except (LookupError, UnicodeError): | |
| charset = charset[2] | |
| # charset character must be in us-ascii range | |
| try: | |
| if isinstance(charset, str): | |
| charset = unicode(charset, 'us-ascii') | |
| charset = 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 |