~dkuhlman/python-training-materials/Materials

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
:mod:`email.utils`: Miscellaneous utilities
-------------------------------------------

.. module:: email.utils
   :synopsis: Miscellaneous email package utilities.


There are several useful utilities provided in the :mod:`email.utils` module:


.. function:: quote(str)

   Return a new string with backslashes in *str* replaced by two backslashes, and
   double quotes replaced by backslash-double quote.


.. function:: unquote(str)

   Return a new string which is an *unquoted* version of *str*. If *str* ends and
   begins with double quotes, they are stripped off.  Likewise if *str* ends and
   begins with angle brackets, they are stripped off.


.. function:: parseaddr(address)

   Parse address -- which should be the value of some address-containing field such
   as :mailheader:`To` or :mailheader:`Cc` -- into its constituent *realname* and
   *email address* parts.  Returns a tuple of that information, unless the parse
   fails, in which case a 2-tuple of ``('', '')`` is returned.


.. function:: formataddr(pair)

   The inverse of :meth:`parseaddr`, this takes a 2-tuple of the form ``(realname,
   email_address)`` and returns the string value suitable for a :mailheader:`To` or
   :mailheader:`Cc` header.  If the first element of *pair* is false, then the
   second element is returned unmodified.


.. function:: getaddresses(fieldvalues)

   This method returns a list of 2-tuples of the form returned by ``parseaddr()``.
   *fieldvalues* is a sequence of header field values as might be returned by
   :meth:`Message.get_all <email.message.Message.get_all>`.  Here's a simple
   example that gets all the recipients of a message::

      from email.utils import getaddresses

      tos = msg.get_all('to', [])
      ccs = msg.get_all('cc', [])
      resent_tos = msg.get_all('resent-to', [])
      resent_ccs = msg.get_all('resent-cc', [])
      all_recipients = getaddresses(tos + ccs + resent_tos + resent_ccs)


.. function:: parsedate(date)

   Attempts to parse a date according to the rules in :rfc:`2822`. however, some
   mailers don't follow that format as specified, so :func:`parsedate` tries to
   guess correctly in such cases.  *date* is a string containing an :rfc:`2822`
   date, such as  ``"Mon, 20 Nov 1995 19:12:08 -0500"``.  If it succeeds in parsing
   the date, :func:`parsedate` returns a 9-tuple that can be passed directly to
   :func:`time.mktime`; otherwise ``None`` will be returned.  Note that indexes 6,
   7, and 8 of the result tuple are not usable.


.. function:: parsedate_tz(date)

   Performs the same function as :func:`parsedate`, but returns either ``None`` or
   a 10-tuple; the first 9 elements make up a tuple that can be passed directly to
   :func:`time.mktime`, and the tenth is the offset of the date's timezone from UTC
   (which is the official term for Greenwich Mean Time) [#]_.  If the input string
   has no timezone, the last element of the tuple returned is ``None``.  Note that
   indexes 6, 7, and 8 of the result tuple are not usable.


.. function:: mktime_tz(tuple)

   Turn a 10-tuple as returned by :func:`parsedate_tz` into a UTC
   timestamp (seconds since the Epoch).  If the timezone item in the
   tuple is ``None``, assume local time.


.. function:: formatdate([timeval[, localtime][, usegmt]])

   Returns a date string as per :rfc:`2822`, e.g.::

      Fri, 09 Nov 2001 01:08:47 -0000

   Optional *timeval* if given is a floating point time value as accepted by
   :func:`time.gmtime` and :func:`time.localtime`, otherwise the current time is
   used.

   Optional *localtime* is a flag that when ``True``, interprets *timeval*, and
   returns a date relative to the local timezone instead of UTC, properly taking
   daylight savings time into account. The default is ``False`` meaning UTC is
   used.

   Optional *usegmt* is a flag that when ``True``, outputs a  date string with the
   timezone as an ascii string ``GMT``, rather than a numeric ``-0000``. This is
   needed for some protocols (such as HTTP). This only applies when *localtime* is
   ``False``.  The default is ``False``.

   .. versionadded:: 2.4


.. function:: make_msgid([idstring])

   Returns a string suitable for an :rfc:`2822`\ -compliant
   :mailheader:`Message-ID` header.  Optional *idstring* if given, is a string used
   to strengthen the uniqueness of the message id.


.. function:: decode_rfc2231(s)

   Decode the string *s* according to :rfc:`2231`.


.. function:: encode_rfc2231(s[, charset[, language]])

   Encode the string *s* according to :rfc:`2231`.  Optional *charset* and
   *language*, if given is the character set name and language name to use.  If
   neither is given, *s* is returned as-is.  If *charset* is given but *language*
   is not, the string is encoded using the empty string for *language*.


.. function:: collapse_rfc2231_value(value[, errors[, fallback_charset]])

   When a header parameter is encoded in :rfc:`2231` format,
   :meth:`Message.get_param <email.message.Message.get_param>` may return a
   3-tuple containing the character set,
   language, and value.  :func:`collapse_rfc2231_value` turns this into a unicode
   string.  Optional *errors* is passed to the *errors* argument of the built-in
   :func:`unicode` function; it defaults to ``replace``.  Optional
   *fallback_charset* specifies the character set to use if the one in the
   :rfc:`2231` header is not known by Python; it defaults to ``us-ascii``.

   For convenience, if the *value* passed to :func:`collapse_rfc2231_value` is not
   a tuple, it should be a string and it is returned unquoted.


.. function:: decode_params(params)

   Decode parameters list according to :rfc:`2231`.  *params* is a sequence of
   2-tuples containing elements of the form ``(content-type, string-value)``.

.. versionchanged:: 2.4
   The :func:`dump_address_pair` function has been removed; use :func:`formataddr`
   instead.

.. versionchanged:: 2.4
   The :func:`decode` function has been removed; use the
   :meth:`Header.decode_header <email.header.Header.decode_header>` method
   instead.

.. versionchanged:: 2.4
   The :func:`encode` function has been removed; use the :meth:`Header.encode
   <email.header.Header.encode>` method instead.

.. rubric:: Footnotes

.. [#] Note that the sign of the timezone offset is the opposite of the sign of the
   ``time.timezone`` variable for the same timezone; the latter variable follows
   the POSIX standard while this module follows :rfc:`2822`.