19.1.12. email.utils
: Miscellaneous utilities¶
Source code: Lib/email/utils.py
There are several useful utilities provided in the email.utils
module:
-
email.utils.
quote
(str)¶ Return a new string with backslashes in str replaced by two backslashes, and double quotes replaced by backslash-double quote.
-
email.utils.
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.
-
email.utils.
parseaddr
(address)¶ Parse address – which should be the value of some address-containing field such as To or 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.
-
email.utils.
formataddr
(pair, charset='utf-8')¶ The inverse of
parseaddr()
, this takes a 2-tuple of the form(realname, email_address)
and returns the string value suitable for a To or Cc header. If the first element of pair is false, then the second element is returned unmodified.Optional charset is the character set that will be used in the RFC 2047 encoding of the
realname
if therealname
contains non-ASCII characters. Can be an instance ofstr
or aCharset
. Defaults toutf-8
.Distinto en la versión 3.3: Added the charset option.
-
email.utils.
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 byMessage.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)
-
email.utils.
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
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,parsedate()
returns a 9-tuple that can be passed directly totime.mktime()
; otherwiseNone
will be returned. Note that indexes 6, 7, and 8 of the result tuple are not usable.
-
email.utils.
parsedate_tz
(date)¶ Performs the same function as
parsedate()
, but returns eitherNone
or a 10-tuple; the first 9 elements make up a tuple that can be passed directly totime.mktime()
, and the tenth is the offset of the date’s timezone from UTC (which is the official term for Greenwich Mean Time) [1]. If the input string has no timezone, the last element of the tuple returned isNone
. Note that indexes 6, 7, and 8 of the result tuple are not usable.
-
email.utils.
parsedate_to_datetime
(date)¶ The inverse of
format_datetime()
. Performs the same function asparsedate()
, but on success returns adatetime
. If the input date has a timezone of-0000
, thedatetime
will be a naivedatetime
, and if the date is conforming to the RFCs it will represent a time in UTC but with no indication of the actual source timezone of the message the date comes from. If the input date has any other valid timezone offset, thedatetime
will be an awaredatetime
with the corresponding atimezone
tzinfo
.Nuevo en la versión 3.3.
-
email.utils.
mktime_tz
(tuple)¶ Turn a 10-tuple as returned by
parsedate_tz()
into a UTC timestamp (seconds since the Epoch). If the timezone item in the tuple isNone
, assume local time.
-
email.utils.
formatdate
(timeval=None, localtime=False, usegmt=False)¶ 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
time.gmtime()
andtime.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 isFalse
meaning UTC is used.Optional usegmt is a flag that when
True
, outputs a date string with the timezone as an ascii stringGMT
, rather than a numeric-0000
. This is needed for some protocols (such as HTTP). This only applies when localtime isFalse
. The default isFalse
.
-
email.utils.
format_datetime
(dt, usegmt=False)¶ Like
formatdate
, but the input is adatetime
instance. If it is a naive datetime, it is assumed to be «UTC with no information about the source timezone», and the conventional-0000
is used for the timezone. If it is an awaredatetime
, then the numeric timezone offset is used. If it is an aware timezone with offset zero, then usegmt may be set toTrue
, in which case the stringGMT
is used instead of the numeric timezone offset. This provides a way to generate standards conformant HTTP date headers.Nuevo en la versión 3.3.
-
email.utils.
localtime
(dt=None)¶ Return local time as an aware datetime object. If called without arguments, return current time. Otherwise dt argument should be a
datetime
instance, and it is converted to the local time zone according to the system time zone database. If dt is naive (that is,dt.tzinfo
isNone
), it is assumed to be in local time. In this case, a positive or zero value for isdst causeslocaltime
to presume initially that summer time (for example, Daylight Saving Time) is or is not (respectively) in effect for the specified time. A negative value for isdst causes thelocaltime
to attempt to divine whether summer time is in effect for the specified time.Nuevo en la versión 3.3.
-
email.utils.
make_msgid
(idstring=None, domain=None)¶ Returns a string suitable for an RFC 2822-compliant Message-ID header. Optional idstring if given, is a string used to strengthen the uniqueness of the message id. Optional domain if given provides the portion of the msgid after the “@”. The default is the local hostname. It is not normally necessary to override this default, but may be useful certain cases, such as a constructing distributed system that uses a consistent domain name across multiple hosts.
Distinto en la versión 3.2: Added the domain keyword.
-
email.utils.
encode_rfc2231
(s, charset=None, language=None)¶ 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.
-
email.utils.
collapse_rfc2231_value
(value, errors='replace', fallback_charset='us-ascii')¶ When a header parameter is encoded in RFC 2231 format,
Message.get_param
may return a 3-tuple containing the character set, language, and value.collapse_rfc2231_value()
turns this into a unicode string. Optional errors is passed to the errors argument ofstr
’sencode()
method; 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
collapse_rfc2231_value()
is not a tuple, it should be a string and it is returned unquoted.
-
email.utils.
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)
.
Footnotes
[1] | 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. |