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diff --git a/Doc/library/email.util.rst b/Doc/library/email.util.rst new file mode 100644 index 0000000000..aa6788549f --- /dev/null +++ b/Doc/library/email.util.rst @@ -0,0 +1,166 @@ +:mod:`email`: 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`. 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. It + the timezone item in the tuple is ``None``, assume local time. Minor + deficiency: :func:`mktime_tz` interprets the first 8 elements of *tuple* as a + local time and then compensates for the timezone difference. This may yield a + slight error around changes in daylight savings time, though not worth worrying + about for common use. + + +.. 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``. + + .. 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` 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` method instead. + +.. versionchanged:: 2.4 + The :func:`encode` function has been removed; use the :meth:`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`. + |