symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/email.util.rst
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     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 
       
    87 .. function:: formatdate([timeval[, localtime][, usegmt]])
       
    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
       
   105    ``False``.
       
   106 
       
   107    .. versionadded:: 2.4
       
   108 
       
   109 
       
   110 .. function:: make_msgid([idstring])
       
   111 
       
   112    Returns a string suitable for an :rfc:`2822`\ -compliant
       
   113    :mailheader:`Message-ID` header.  Optional *idstring* if given, is a string used
       
   114    to strengthen the uniqueness of the message id.
       
   115 
       
   116 
       
   117 .. function:: decode_rfc2231(s)
       
   118 
       
   119    Decode the string *s* according to :rfc:`2231`.
       
   120 
       
   121 
       
   122 .. function:: encode_rfc2231(s[, charset[, language]])
       
   123 
       
   124    Encode the string *s* according to :rfc:`2231`.  Optional *charset* and
       
   125    *language*, if given is the character set name and language name to use.  If
       
   126    neither is given, *s* is returned as-is.  If *charset* is given but *language*
       
   127    is not, the string is encoded using the empty string for *language*.
       
   128 
       
   129 
       
   130 .. function:: collapse_rfc2231_value(value[, errors[, fallback_charset]])
       
   131 
       
   132    When a header parameter is encoded in :rfc:`2231` format,
       
   133    :meth:`Message.get_param` may return a 3-tuple containing the character set,
       
   134    language, and value.  :func:`collapse_rfc2231_value` turns this into a unicode
       
   135    string.  Optional *errors* is passed to the *errors* argument of the built-in
       
   136    :func:`unicode` function; it defaults to ``replace``.  Optional
       
   137    *fallback_charset* specifies the character set to use if the one in the
       
   138    :rfc:`2231` header is not known by Python; it defaults to ``us-ascii``.
       
   139 
       
   140    For convenience, if the *value* passed to :func:`collapse_rfc2231_value` is not
       
   141    a tuple, it should be a string and it is returned unquoted.
       
   142 
       
   143 
       
   144 .. function:: decode_params(params)
       
   145 
       
   146    Decode parameters list according to :rfc:`2231`.  *params* is a sequence of
       
   147    2-tuples containing elements of the form ``(content-type, string-value)``.
       
   148 
       
   149 .. versionchanged:: 2.4
       
   150    The :func:`dump_address_pair` function has been removed; use :func:`formataddr`
       
   151    instead.
       
   152 
       
   153 .. versionchanged:: 2.4
       
   154    The :func:`decode` function has been removed; use the
       
   155    :meth:`Header.decode_header` method instead.
       
   156 
       
   157 .. versionchanged:: 2.4
       
   158    The :func:`encode` function has been removed; use the :meth:`Header.encode`
       
   159    method instead.
       
   160 
       
   161 .. rubric:: Footnotes
       
   162 
       
   163 .. [#] Note that the sign of the timezone offset is the opposite of the sign of the
       
   164    ``time.timezone`` variable for the same timezone; the latter variable follows
       
   165    the POSIX standard while this module follows :rfc:`2822`.
       
   166