AlwaysStdErrHandler

class scikitplot.logging.AlwaysStdErrHandler(stream=None)

A custom logging handler inherited from StreamHandler.

That enforces the use of a specific output stream: either standard error (sys.stderr) or standard output (sys.stdout).

This handler is particularly useful for environments where log streams must be explicitly directed, such as Jupyter notebooks or specialized logging setups.

Parameters:

stream{‘stdout’, ‘stderr’} or IO[str], optional

If a string is provided, selects sys.stdout or sys.stderr. If a file-like object is provided, it will be used directly. Default is 'stderr' (or 'stdout' when detected in Jupyter).

Raises:

ValueError

If stream is a string not in {'stdout', 'stderr'}.

Parameters:

stream (str | any | None)

See also

logging.StreamHandler

Writes logging records, appropriately formatted, to a stream. This class does not close the stream, as sys.stdout or sys.stderr may be used.

_is_jupyter_notebook

Determines if the environment is a Jupyter notebook. For define use_stderr.

Notes

Historically, this handler tried to default to stderr except in notebooks. This behavior is preserved through the default arguments in the base class.

acquire()

Acquire the I/O thread lock.

addFilter(filter)

Add the specified filter to this handler.

close()

Tidy up any resources used by the handler.

This version removes the handler from an internal map of handlers, _handlers, which is used for handler lookup by name. Subclasses should ensure that this gets called from overridden close() methods.

createLock()

Acquire a thread lock for serializing access to the underlying I/O.

emit(record)

Emit a record.

If a formatter is specified, it is used to format the record. The record is then written to the stream with a trailing newline. If exception information is present, it is formatted using traceback.print_exception and appended to the stream. If the stream has an ‘encoding’ attribute, it is used to determine how to do the output to the stream.

filter(record)

Determine if a record is loggable by consulting all the filters.

The default is to allow the record to be logged; any filter can veto this by returning a false value. If a filter attached to a handler returns a log record instance, then that instance is used in place of the original log record in any further processing of the event by that handler. If a filter returns any other true value, the original log record is used in any further processing of the event by that handler.

If none of the filters return false values, this method returns a log record. If any of the filters return a false value, this method returns a false value.

Changed in version 3.2: Allow filters to be just callables.

Changed in version 3.12: Allow filters to return a LogRecord instead of modifying it in place.

flush()

Flushes the stream.

format(record)

Format the specified record.

If a formatter is set, use it. Otherwise, use the default formatter for the module.

get_name()

handle(record)

Conditionally emit the specified logging record.

Emission depends on filters which may have been added to the handler. Wrap the actual emission of the record with acquisition/release of the I/O thread lock.

Returns an instance of the log record that was emitted if it passed all filters, otherwise a false value is returned.

handleError(record)

Handle errors which occur during an emit() call.

This method should be called from handlers when an exception is encountered during an emit() call. If raiseExceptions is false, exceptions get silently ignored. This is what is mostly wanted for a logging system - most users will not care about errors in the logging system, they are more interested in application errors. You could, however, replace this with a custom handler if you wish. The record which was being processed is passed in to this method.

property name

This is the name property for StreamHandler.

Returns:

str | None

The current handler object name if provided, otherwise None.

release()

Release the I/O thread lock.

removeFilter(filter)

Remove the specified filter from this handler.

setFormatter(fmt)

Set the formatter for this handler.

setLevel(level)

Set the logging level of this handler. level must be an int or a str.

setStream(stream)

Sets the StreamHandler’s stream to the specified value, if it is different.

Returns the old stream, if the stream was changed, or None if it wasn’t.

set_name(name)

property stream: IO[str]

Get the current logging stream.

Returns:

IO[str]

The current stream object (sys.stderr or sys.stdout).

terminator = '\n'