Formatter instances are used to convert a LogRecord to text.
Formatters need to know how a LogRecord is constructed. They are responsible for converting a LogRecord to (usually) a string which can be interpreted by either a human or an external system. The base Formatter allows a formatting string to be specified. If none is supplied, the default value of "%s(message)\n" is used.
The Formatter can be initialized with a format string which makes use of knowledge of the LogRecord attributes - e.g. the default value mentioned above makes use of the fact that the user's message and arguments are pre- formatted into a LogRecord's message attribute. Currently, the useful attributes in a LogRecord are described by:
%(name)s Name of the logger (logging channel) %(levelno)s Numeric logging level for the message (DEBUG, INFO, WARNING, ERROR, CRITICAL) %(levelname)s Text logging level for the message ("DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL") %(pathname)s Full pathname of the source file where the logging call was issued (if available) %(filename)s Filename portion of pathname %(module)s Module (name portion of filename) %(lineno)d Source line number where the logging call was issued (if available) %(created)f Time when the LogRecord was created (time.time() return value) %(asctime)s Textual time when the LogRecord was created %(msecs)d Millisecond portion of the creation time %(relativeCreated)d Time in milliseconds when the LogRecord was created, relative to the time the logging module was loaded (typically at application startup time) %(thread)d Thread ID (if available) %(threadName)s Thread name (if available) %(process)d Process ID (if available) %(message)s The result of record.getMessage(), computed just as the record is emitted
There are no base classes.
There are no implemented interfaces.
converter
(type: builtin_function_or_method
)
<built-in function localtime>
format(record)
Format the specified record as text.
The record's attribute dictionary is used as the operand to a string formatting operation which yields the returned string. Before formatting the dictionary, a couple of preparatory steps are carried out. The message attribute of the record is computed using LogRecord.getMessage(). If the formatting string contains "%(asctime)", formatTime() is called to format the event time. If there is exception information, it is formatted using formatException() and appended to the message.
formatException(ei)
Format and return the specified exception information as a string.
This default implementation just uses traceback.print_exception()
formatTime(record, datefmt=None)
Return the creation time of the specified LogRecord as formatted text.
This method should be called from format() by a formatter which
wants to make use of a formatted time. This method can be overridden
in formatters to provide for any specific requirement, but the
basic behaviour is as follows: if datefmt (a string) is specified,
it is used with time.strftime() to format the creation time of the
record. Otherwise, the ISO8601 format is used. The resulting
string is returned. This function uses a user-configurable function
to convert the creation time to a tuple. By default, time.localtime()
is used; to change this for a particular formatter instance, set the
converter
attribute to a function with the same signature as
time.localtime() or time.gmtime(). To change it for all formatters,
for example if you want all logging times to be shown in GMT,
set the converter
attribute in the Formatter class.
There are no known subclasses.