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Diffstat (limited to 'Doc/library/logging.rst')
| -rw-r--r-- | Doc/library/logging.rst | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/Doc/library/logging.rst b/Doc/library/logging.rst index cb613ce..9023738 100644 --- a/Doc/library/logging.rst +++ b/Doc/library/logging.rst @@ -301,17 +301,29 @@ Formatters Formatter objects configure the final order, structure, and contents of the log message. Unlike the base :class:`logging.Handler` class, application code may instantiate formatter classes, although you could likely subclass the formatter -if your application needs special behavior. The constructor takes two optional -arguments: a message format string and a date format string. If there is no -message format string, the default is to use the raw message. If there is no -date format string, the default date format is:: +if your application needs special behavior. The constructor takes three +optional arguments -- a message format string, a date format string and a style +indicator. + +.. method:: logging.Formatter.__init__(fmt=None, datefmt=None, style='%') + +If there is no message format string, the default is to use the +raw message. If there is no date format string, the default date format is:: %Y-%m-%d %H:%M:%S -with the milliseconds tacked on at the end. +with the milliseconds tacked on at the end. The ``style`` is one of `%`, '{' +or '$'. If one of these is not specified, then '%' will be used. -The message format string uses ``%(<dictionary key>)s`` styled string -substitution; the possible keys are documented in :ref:`formatter-objects`. +If the ``style`` is '%', the message format string uses +``%(<dictionary key>)s`` styled string substitution; the possible keys are +documented in :ref:`formatter-objects`. If the style is '{', the message format +string is assumed to be compatible with :meth:`str.format` (using keyword +arguments), while if the style is '$' then the message format string should +conform to what is expected by :meth:`string.Template.substitute`. + +.. versionchanged:: 3.2 + Added the ``style`` parameter. The following message format string will log the time in a human-readable format, the severity of the message, and the contents of the message, in that |