twisted.python.log
module documentationtwisted.python
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Logging and metrics infrastructure.
Class | ILogContext | Actually, this interface is just a synonym for the dictionary interface, but it serves as a key for the default information in a log. |
Interface | ILogObserver | An observer which can do something with log events. |
Function | callWithContext | Undocumented |
Function | callWithLogger | Utility method which wraps a function in a try:/except:, logs a failure if one occurs, and uses the system's logPrefix. |
Function | err | Write a failure to the log. |
Class | Logger | This represents a class which may 'own' a log. Used by subclassing. |
Class | LogPublisher | Class for singleton log message publishing. |
Function | addObserver | Add a log observer to the global publisher. |
Function | removeObserver | Remove a log observer from the global publisher. |
Function | msg | Publish a message to the global log publisher. |
Function | showwarning | Publish a Python warning through the global log publisher. |
Function | textFromEventDict | Extract text from an event dict passed to a log observer. If it cannot handle the dict, it returns None. |
Class | FileLogObserver | Log observer that writes to a file-like object. |
Class | PythonLoggingObserver | Output twisted messages to Python standard library logging
module. |
Class | StdioOnnaStick | Class that pretends to be stdout/err, and turns writes into log messages. |
Function | startLogging | Initialize logging to a specified file. |
Function | startLoggingWithObserver | Initialize logging to a specified observer. If setStdout is true (defaults to yes), also redirect sys.stdout and sys.stderr to the specified file. |
Class | NullFile | A file-like object that discards everything. |
Function | discardLogs | Discard messages logged via the global logfile object. |
Class | DefaultObserver | Default observer. |
Function | _actually | A decorator that returns its argument rather than the thing it is decorating. |
Function | _safeFormat | Try to format a string, swallowing all errors to always return a string. |
Class | _GlobalStartStopMixIn | Mix-in for global log observers that can start and stop. |
Utility method which wraps a function in a try:/except:, logs a failure if one occurs, and uses the system's logPrefix.
Write a failure to the log.
The _stuff
and _why
parameters use an
underscore prefix to lessen the chance of colliding with a keyword argument
the application wishes to pass. It is intended that they be supplied with
arguments passed positionally, not by keyword.
Parameters | _stuff | The failure to log. If _stuff is None
a new Failure will be
created from the current exception state. If _stuff is an
Exception instance it will be wrapped in a Failure . (type: None ,
Exception , or Failure .) |
_why | The source of this failure. This will be logged along with
_stuff and should describe the context in which the failure
occurred. (type: str ) |
A decorator that returns its argument rather than the thing it is decorating.
This allows the documentation generator to see an alias for a method or constant as an object with a docstring and thereby document it and allow references to it statically.
Parameters | something | An object to create an alias for. (type: object ) |
Returns | a 1-argument callable that returns something (type: object ) |
Add a log observer to the global publisher.
Parameters | observer | a log observer (type: callable ) |
See Also | LogPublisher.addObserver |
Remove a log observer from the global publisher.
Parameters | observer | a log observer previously added with addObserver (type: callable ) |
See Also | LogPublisher.removeObserver |
Publish a message to the global log publisher.
Parameters | message | the log message (type: tuple of str
(native string)) |
event | fields for the log event (type: dict
mapping str
(native string) to object ) | |
See Also | LogPublisher.msg |
Publish a Python warning through the global log publisher.
See Also | LogPublisher.showwarning |
Try to format a string, swallowing all errors to always return a string.
Parameters | fmtString | a % -format string |
fmtDict | string formatting arguments for fmtString | |
Returns | A native string, formatted from fmtString and
fmtDict . (type: str ) | |
Note | For backward-compatibility reasons, this function ensures that it returns a
native string, meaning bytes in Python 2 and
unicode in Python 3. |
Extract text from an event dict passed to a log observer. If it cannot handle the dict, it returns None.
The possible keys of eventDict are:
message
: by default, it holds the final text. It's
required, but can be empty if either isError
or
format
is provided (the first having the priority).
isError
: boolean indicating the nature of the event.
failure
: failure.Failure
instance, required if the event is an error.
why
: if defined, used as header of the traceback in case
of errors.
format
: string format used in place of
message
to customize the event. It uses all keys present
in eventDict
to format the text.
Other keys will be used when applying the format
, or
ignored.
Initialize logging to a specified file.
Returns | A FileLogObserver
if a new observer is added, None otherwise. |
Initialize logging to a specified observer. If setStdout is true (defaults to yes), also redirect sys.stdout and sys.stderr to the specified file.