Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1 | :mod:`email`: Miscellaneous utilities |
| 2 | ------------------------------------- |
| 3 | |
| 4 | .. module:: email.utils |
| 5 | :synopsis: Miscellaneous email package utilities. |
| 6 | |
| 7 | |
| 8 | There are several useful utilities provided in the :mod:`email.utils` module: |
| 9 | |
| 10 | |
| 11 | .. function:: quote(str) |
| 12 | |
| 13 | Return a new string with backslashes in *str* replaced by two backslashes, and |
| 14 | double quotes replaced by backslash-double quote. |
| 15 | |
| 16 | |
| 17 | .. function:: unquote(str) |
| 18 | |
| 19 | Return a new string which is an *unquoted* version of *str*. If *str* ends and |
| 20 | begins with double quotes, they are stripped off. Likewise if *str* ends and |
| 21 | begins with angle brackets, they are stripped off. |
| 22 | |
| 23 | |
| 24 | .. function:: parseaddr(address) |
| 25 | |
| 26 | Parse address -- which should be the value of some address-containing field such |
| 27 | as :mailheader:`To` or :mailheader:`Cc` -- into its constituent *realname* and |
| 28 | *email address* parts. Returns a tuple of that information, unless the parse |
| 29 | fails, in which case a 2-tuple of ``('', '')`` is returned. |
| 30 | |
| 31 | |
| 32 | .. function:: formataddr(pair) |
| 33 | |
| 34 | The inverse of :meth:`parseaddr`, this takes a 2-tuple of the form ``(realname, |
| 35 | email_address)`` and returns the string value suitable for a :mailheader:`To` or |
| 36 | :mailheader:`Cc` header. If the first element of *pair* is false, then the |
| 37 | second element is returned unmodified. |
| 38 | |
| 39 | |
| 40 | .. function:: getaddresses(fieldvalues) |
| 41 | |
| 42 | This method returns a list of 2-tuples of the form returned by ``parseaddr()``. |
| 43 | *fieldvalues* is a sequence of header field values as might be returned by |
| 44 | :meth:`Message.get_all`. Here's a simple example that gets all the recipients |
| 45 | of a message:: |
| 46 | |
| 47 | from email.utils import getaddresses |
| 48 | |
| 49 | tos = msg.get_all('to', []) |
| 50 | ccs = msg.get_all('cc', []) |
| 51 | resent_tos = msg.get_all('resent-to', []) |
| 52 | resent_ccs = msg.get_all('resent-cc', []) |
| 53 | all_recipients = getaddresses(tos + ccs + resent_tos + resent_ccs) |
| 54 | |
| 55 | |
| 56 | .. function:: parsedate(date) |
| 57 | |
| 58 | Attempts to parse a date according to the rules in :rfc:`2822`. however, some |
| 59 | mailers don't follow that format as specified, so :func:`parsedate` tries to |
| 60 | guess correctly in such cases. *date* is a string containing an :rfc:`2822` |
| 61 | date, such as ``"Mon, 20 Nov 1995 19:12:08 -0500"``. If it succeeds in parsing |
| 62 | the date, :func:`parsedate` returns a 9-tuple that can be passed directly to |
| 63 | :func:`time.mktime`; otherwise ``None`` will be returned. Note that indexes 6, |
| 64 | 7, and 8 of the result tuple are not usable. |
| 65 | |
| 66 | |
| 67 | .. function:: parsedate_tz(date) |
| 68 | |
| 69 | Performs the same function as :func:`parsedate`, but returns either ``None`` or |
| 70 | a 10-tuple; the first 9 elements make up a tuple that can be passed directly to |
| 71 | :func:`time.mktime`, and the tenth is the offset of the date's timezone from UTC |
| 72 | (which is the official term for Greenwich Mean Time) [#]_. If the input string |
| 73 | has no timezone, the last element of the tuple returned is ``None``. Note that |
| 74 | indexes 6, 7, and 8 of the result tuple are not usable. |
| 75 | |
| 76 | |
| 77 | .. function:: mktime_tz(tuple) |
| 78 | |
| 79 | Turn a 10-tuple as returned by :func:`parsedate_tz` into a UTC timestamp. It |
| 80 | the timezone item in the tuple is ``None``, assume local time. Minor |
| 81 | deficiency: :func:`mktime_tz` interprets the first 8 elements of *tuple* as a |
| 82 | local time and then compensates for the timezone difference. This may yield a |
| 83 | slight error around changes in daylight savings time, though not worth worrying |
| 84 | about for common use. |
| 85 | |
| 86 | |
Georg Brandl | 3f076d8 | 2009-05-17 11:28:33 +0000 | [diff] [blame] | 87 | .. function:: formatdate(timeval=None, localtime=False, usegmt=False) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 88 | |
| 89 | Returns a date string as per :rfc:`2822`, e.g.:: |
| 90 | |
| 91 | Fri, 09 Nov 2001 01:08:47 -0000 |
| 92 | |
| 93 | Optional *timeval* if given is a floating point time value as accepted by |
| 94 | :func:`time.gmtime` and :func:`time.localtime`, otherwise the current time is |
| 95 | used. |
| 96 | |
| 97 | Optional *localtime* is a flag that when ``True``, interprets *timeval*, and |
| 98 | returns a date relative to the local timezone instead of UTC, properly taking |
| 99 | daylight savings time into account. The default is ``False`` meaning UTC is |
| 100 | used. |
| 101 | |
| 102 | Optional *usegmt* is a flag that when ``True``, outputs a date string with the |
| 103 | timezone as an ascii string ``GMT``, rather than a numeric ``-0000``. This is |
| 104 | needed for some protocols (such as HTTP). This only applies when *localtime* is |
R. David Murray | 13cc4fd | 2010-02-04 16:44:31 +0000 | [diff] [blame] | 105 | ``False``. The default is ``False``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 106 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 107 | |
Georg Brandl | 3f076d8 | 2009-05-17 11:28:33 +0000 | [diff] [blame] | 108 | .. function:: make_msgid(idstring=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 109 | |
| 110 | Returns a string suitable for an :rfc:`2822`\ -compliant |
Georg Brandl | 3f076d8 | 2009-05-17 11:28:33 +0000 | [diff] [blame] | 111 | :mailheader:`Message-ID` header. Optional *idstring* if given, is a string |
| 112 | used to strengthen the uniqueness of the message id. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 113 | |
| 114 | |
| 115 | .. function:: decode_rfc2231(s) |
| 116 | |
| 117 | Decode the string *s* according to :rfc:`2231`. |
| 118 | |
| 119 | |
Georg Brandl | 3f076d8 | 2009-05-17 11:28:33 +0000 | [diff] [blame] | 120 | .. function:: encode_rfc2231(s, charset=None, language=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 121 | |
| 122 | Encode the string *s* according to :rfc:`2231`. Optional *charset* and |
| 123 | *language*, if given is the character set name and language name to use. If |
| 124 | neither is given, *s* is returned as-is. If *charset* is given but *language* |
| 125 | is not, the string is encoded using the empty string for *language*. |
| 126 | |
| 127 | |
Georg Brandl | 3f076d8 | 2009-05-17 11:28:33 +0000 | [diff] [blame] | 128 | .. function:: collapse_rfc2231_value(value, errors='replace', fallback_charset='us-ascii') |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 129 | |
| 130 | When a header parameter is encoded in :rfc:`2231` format, |
| 131 | :meth:`Message.get_param` may return a 3-tuple containing the character set, |
| 132 | language, and value. :func:`collapse_rfc2231_value` turns this into a unicode |
Georg Brandl | f694518 | 2008-02-01 11:56:49 +0000 | [diff] [blame] | 133 | string. Optional *errors* is passed to the *errors* argument of :class:`str`'s |
| 134 | :func:`encode` method; it defaults to ``'replace'``. Optional |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 135 | *fallback_charset* specifies the character set to use if the one in the |
Georg Brandl | f694518 | 2008-02-01 11:56:49 +0000 | [diff] [blame] | 136 | :rfc:`2231` header is not known by Python; it defaults to ``'us-ascii'``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 137 | |
| 138 | For convenience, if the *value* passed to :func:`collapse_rfc2231_value` is not |
| 139 | a tuple, it should be a string and it is returned unquoted. |
| 140 | |
| 141 | |
| 142 | .. function:: decode_params(params) |
| 143 | |
| 144 | Decode parameters list according to :rfc:`2231`. *params* is a sequence of |
| 145 | 2-tuples containing elements of the form ``(content-type, string-value)``. |
| 146 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 147 | |
| 148 | .. rubric:: Footnotes |
| 149 | |
| 150 | .. [#] Note that the sign of the timezone offset is the opposite of the sign of the |
| 151 | ``time.timezone`` variable for the same timezone; the latter variable follows |
| 152 | the POSIX standard while this module follows :rfc:`2822`. |
| 153 | |