我写了一个完整的替代品sys.stderr
,只是重复了代码重命名stderr
,stdout
以使其也可以替代sys.stdout
。
为此,我创建与current stderr
和相同的对象类型stdout
,并将所有方法转发到原始系统stderr
和stdout
:
import os
import sys
import logging
class StdErrReplament(object):
"""
How to redirect stdout and stderr to logger in Python
/programming/19425736/how-to-redirect-stdout-and-stderr-to-logger-in-python
Set a Read-Only Attribute in Python?
/programming/24497316/set-a-read-only-attribute-in-python
"""
is_active = False
@classmethod
def lock(cls, logger):
"""
Attach this singleton logger to the `sys.stderr` permanently.
"""
global _stderr_singleton
global _stderr_default
global _stderr_default_class_type
# On Sublime Text, `sys.__stderr__` is set to None, because they already replaced `sys.stderr`
# by some `_LogWriter()` class, then just save the current one over there.
if not sys.__stderr__:
sys.__stderr__ = sys.stderr
try:
_stderr_default
_stderr_default_class_type
except NameError:
_stderr_default = sys.stderr
_stderr_default_class_type = type( _stderr_default )
# Recreate the sys.stderr logger when it was reset by `unlock()`
if not cls.is_active:
cls.is_active = True
_stderr_write = _stderr_default.write
logger_call = logger.debug
clean_formatter = logger.clean_formatter
global _sys_stderr_write
global _sys_stderr_write_hidden
if sys.version_info <= (3,2):
logger.file_handler.terminator = '\n'
# Always recreate/override the internal write function used by `_sys_stderr_write`
def _sys_stderr_write_hidden(*args, **kwargs):
"""
Suppress newline in Python logging module
/programming/7168790/suppress-newline-in-python-logging-module
"""
try:
_stderr_write( *args, **kwargs )
file_handler = logger.file_handler
formatter = file_handler.formatter
terminator = file_handler.terminator
file_handler.formatter = clean_formatter
file_handler.terminator = ""
kwargs['extra'] = {'_duplicated_from_file': True}
logger_call( *args, **kwargs )
file_handler.formatter = formatter
file_handler.terminator = terminator
except Exception:
logger.exception( "Could not write to the file_handler: %s(%s)", file_handler, logger )
cls.unlock()
# Only create one `_sys_stderr_write` function pointer ever
try:
_sys_stderr_write
except NameError:
def _sys_stderr_write(*args, **kwargs):
"""
Hides the actual function pointer. This allow the external function pointer to
be cached while the internal written can be exchanged between the standard
`sys.stderr.write` and our custom wrapper around it.
"""
_sys_stderr_write_hidden( *args, **kwargs )
try:
# Only create one singleton instance ever
_stderr_singleton
except NameError:
class StdErrReplamentHidden(_stderr_default_class_type):
"""
Which special methods bypasses __getattribute__ in Python?
/programming/12872695/which-special-methods-bypasses-getattribute-in-python
"""
if hasattr( _stderr_default, "__abstractmethods__" ):
__abstractmethods__ = _stderr_default.__abstractmethods__
if hasattr( _stderr_default, "__base__" ):
__base__ = _stderr_default.__base__
if hasattr( _stderr_default, "__bases__" ):
__bases__ = _stderr_default.__bases__
if hasattr( _stderr_default, "__basicsize__" ):
__basicsize__ = _stderr_default.__basicsize__
if hasattr( _stderr_default, "__call__" ):
__call__ = _stderr_default.__call__
if hasattr( _stderr_default, "__class__" ):
__class__ = _stderr_default.__class__
if hasattr( _stderr_default, "__delattr__" ):
__delattr__ = _stderr_default.__delattr__
if hasattr( _stderr_default, "__dict__" ):
__dict__ = _stderr_default.__dict__
if hasattr( _stderr_default, "__dictoffset__" ):
__dictoffset__ = _stderr_default.__dictoffset__
if hasattr( _stderr_default, "__dir__" ):
__dir__ = _stderr_default.__dir__
if hasattr( _stderr_default, "__doc__" ):
__doc__ = _stderr_default.__doc__
if hasattr( _stderr_default, "__eq__" ):
__eq__ = _stderr_default.__eq__
if hasattr( _stderr_default, "__flags__" ):
__flags__ = _stderr_default.__flags__
if hasattr( _stderr_default, "__format__" ):
__format__ = _stderr_default.__format__
if hasattr( _stderr_default, "__ge__" ):
__ge__ = _stderr_default.__ge__
if hasattr( _stderr_default, "__getattribute__" ):
__getattribute__ = _stderr_default.__getattribute__
if hasattr( _stderr_default, "__gt__" ):
__gt__ = _stderr_default.__gt__
if hasattr( _stderr_default, "__hash__" ):
__hash__ = _stderr_default.__hash__
if hasattr( _stderr_default, "__init__" ):
__init__ = _stderr_default.__init__
if hasattr( _stderr_default, "__init_subclass__" ):
__init_subclass__ = _stderr_default.__init_subclass__
if hasattr( _stderr_default, "__instancecheck__" ):
__instancecheck__ = _stderr_default.__instancecheck__
if hasattr( _stderr_default, "__itemsize__" ):
__itemsize__ = _stderr_default.__itemsize__
if hasattr( _stderr_default, "__le__" ):
__le__ = _stderr_default.__le__
if hasattr( _stderr_default, "__lt__" ):
__lt__ = _stderr_default.__lt__
if hasattr( _stderr_default, "__module__" ):
__module__ = _stderr_default.__module__
if hasattr( _stderr_default, "__mro__" ):
__mro__ = _stderr_default.__mro__
if hasattr( _stderr_default, "__name__" ):
__name__ = _stderr_default.__name__
if hasattr( _stderr_default, "__ne__" ):
__ne__ = _stderr_default.__ne__
if hasattr( _stderr_default, "__new__" ):
__new__ = _stderr_default.__new__
if hasattr( _stderr_default, "__prepare__" ):
__prepare__ = _stderr_default.__prepare__
if hasattr( _stderr_default, "__qualname__" ):
__qualname__ = _stderr_default.__qualname__
if hasattr( _stderr_default, "__reduce__" ):
__reduce__ = _stderr_default.__reduce__
if hasattr( _stderr_default, "__reduce_ex__" ):
__reduce_ex__ = _stderr_default.__reduce_ex__
if hasattr( _stderr_default, "__repr__" ):
__repr__ = _stderr_default.__repr__
if hasattr( _stderr_default, "__setattr__" ):
__setattr__ = _stderr_default.__setattr__
if hasattr( _stderr_default, "__sizeof__" ):
__sizeof__ = _stderr_default.__sizeof__
if hasattr( _stderr_default, "__str__" ):
__str__ = _stderr_default.__str__
if hasattr( _stderr_default, "__subclasscheck__" ):
__subclasscheck__ = _stderr_default.__subclasscheck__
if hasattr( _stderr_default, "__subclasses__" ):
__subclasses__ = _stderr_default.__subclasses__
if hasattr( _stderr_default, "__subclasshook__" ):
__subclasshook__ = _stderr_default.__subclasshook__
if hasattr( _stderr_default, "__text_signature__" ):
__text_signature__ = _stderr_default.__text_signature__
if hasattr( _stderr_default, "__weakrefoffset__" ):
__weakrefoffset__ = _stderr_default.__weakrefoffset__
if hasattr( _stderr_default, "mro" ):
mro = _stderr_default.mro
def __init__(self):
"""
Override any super class `type( _stderr_default )` constructor, so we can
instantiate any kind of `sys.stderr` replacement object, in case it was already
replaced by something else like on Sublime Text with `_LogWriter()`.
Assures all attributes were statically replaced just above. This should happen in case
some new attribute is added to the python language.
This also ignores the only two methods which are not equal, `__init__()` and `__getattribute__()`.
"""
different_methods = ("__init__", "__getattribute__")
attributes_to_check = set( dir( object ) + dir( type ) )
for attribute in attributes_to_check:
if attribute not in different_methods \
and hasattr( _stderr_default, attribute ):
base_class_attribute = super( _stderr_default_class_type, self ).__getattribute__( attribute )
target_class_attribute = _stderr_default.__getattribute__( attribute )
if base_class_attribute != target_class_attribute:
sys.stderr.write( " The base class attribute `%s` is different from the target class:\n%s\n%s\n\n" % (
attribute, base_class_attribute, target_class_attribute ) )
def __getattribute__(self, item):
if item == 'write':
return _sys_stderr_write
try:
return _stderr_default.__getattribute__( item )
except AttributeError:
return super( _stderr_default_class_type, _stderr_default ).__getattribute__( item )
_stderr_singleton = StdErrReplamentHidden()
sys.stderr = _stderr_singleton
return cls
@classmethod
def unlock(cls):
"""
Detach this `stderr` writer from `sys.stderr` and allow the next call to `lock()` create
a new writer for the stderr.
"""
if cls.is_active:
global _sys_stderr_write_hidden
cls.is_active = False
_sys_stderr_write_hidden = _stderr_default.write
class StdOutReplament(object):
"""
How to redirect stdout and stderr to logger in Python
/programming/19425736/how-to-redirect-stdout-and-stderr-to-logger-in-python
Set a Read-Only Attribute in Python?
/programming/24497316/set-a-read-only-attribute-in-python
"""
is_active = False
@classmethod
def lock(cls, logger):
"""
Attach this singleton logger to the `sys.stdout` permanently.
"""
global _stdout_singleton
global _stdout_default
global _stdout_default_class_type
# On Sublime Text, `sys.__stdout__` is set to None, because they already replaced `sys.stdout`
# by some `_LogWriter()` class, then just save the current one over there.
if not sys.__stdout__:
sys.__stdout__ = sys.stdout
try:
_stdout_default
_stdout_default_class_type
except NameError:
_stdout_default = sys.stdout
_stdout_default_class_type = type( _stdout_default )
# Recreate the sys.stdout logger when it was reset by `unlock()`
if not cls.is_active:
cls.is_active = True
_stdout_write = _stdout_default.write
logger_call = logger.debug
clean_formatter = logger.clean_formatter
global _sys_stdout_write
global _sys_stdout_write_hidden
if sys.version_info <= (3,2):
logger.file_handler.terminator = '\n'
# Always recreate/override the internal write function used by `_sys_stdout_write`
def _sys_stdout_write_hidden(*args, **kwargs):
"""
Suppress newline in Python logging module
/programming/7168790/suppress-newline-in-python-logging-module
"""
try:
_stdout_write( *args, **kwargs )
file_handler = logger.file_handler
formatter = file_handler.formatter
terminator = file_handler.terminator
file_handler.formatter = clean_formatter
file_handler.terminator = ""
kwargs['extra'] = {'_duplicated_from_file': True}
logger_call( *args, **kwargs )
file_handler.formatter = formatter
file_handler.terminator = terminator
except Exception:
logger.exception( "Could not write to the file_handler: %s(%s)", file_handler, logger )
cls.unlock()
# Only create one `_sys_stdout_write` function pointer ever
try:
_sys_stdout_write
except NameError:
def _sys_stdout_write(*args, **kwargs):
"""
Hides the actual function pointer. This allow the external function pointer to
be cached while the internal written can be exchanged between the standard
`sys.stdout.write` and our custom wrapper around it.
"""
_sys_stdout_write_hidden( *args, **kwargs )
try:
# Only create one singleton instance ever
_stdout_singleton
except NameError:
class StdOutReplamentHidden(_stdout_default_class_type):
"""
Which special methods bypasses __getattribute__ in Python?
/programming/12872695/which-special-methods-bypasses-getattribute-in-python
"""
if hasattr( _stdout_default, "__abstractmethods__" ):
__abstractmethods__ = _stdout_default.__abstractmethods__
if hasattr( _stdout_default, "__base__" ):
__base__ = _stdout_default.__base__
if hasattr( _stdout_default, "__bases__" ):
__bases__ = _stdout_default.__bases__
if hasattr( _stdout_default, "__basicsize__" ):
__basicsize__ = _stdout_default.__basicsize__
if hasattr( _stdout_default, "__call__" ):
__call__ = _stdout_default.__call__
if hasattr( _stdout_default, "__class__" ):
__class__ = _stdout_default.__class__
if hasattr( _stdout_default, "__delattr__" ):
__delattr__ = _stdout_default.__delattr__
if hasattr( _stdout_default, "__dict__" ):
__dict__ = _stdout_default.__dict__
if hasattr( _stdout_default, "__dictoffset__" ):
__dictoffset__ = _stdout_default.__dictoffset__
if hasattr( _stdout_default, "__dir__" ):
__dir__ = _stdout_default.__dir__
if hasattr( _stdout_default, "__doc__" ):
__doc__ = _stdout_default.__doc__
if hasattr( _stdout_default, "__eq__" ):
__eq__ = _stdout_default.__eq__
if hasattr( _stdout_default, "__flags__" ):
__flags__ = _stdout_default.__flags__
if hasattr( _stdout_default, "__format__" ):
__format__ = _stdout_default.__format__
if hasattr( _stdout_default, "__ge__" ):
__ge__ = _stdout_default.__ge__
if hasattr( _stdout_default, "__getattribute__" ):
__getattribute__ = _stdout_default.__getattribute__
if hasattr( _stdout_default, "__gt__" ):
__gt__ = _stdout_default.__gt__
if hasattr( _stdout_default, "__hash__" ):
__hash__ = _stdout_default.__hash__
if hasattr( _stdout_default, "__init__" ):
__init__ = _stdout_default.__init__
if hasattr( _stdout_default, "__init_subclass__" ):
__init_subclass__ = _stdout_default.__init_subclass__
if hasattr( _stdout_default, "__instancecheck__" ):
__instancecheck__ = _stdout_default.__instancecheck__
if hasattr( _stdout_default, "__itemsize__" ):
__itemsize__ = _stdout_default.__itemsize__
if hasattr( _stdout_default, "__le__" ):
__le__ = _stdout_default.__le__
if hasattr( _stdout_default, "__lt__" ):
__lt__ = _stdout_default.__lt__
if hasattr( _stdout_default, "__module__" ):
__module__ = _stdout_default.__module__
if hasattr( _stdout_default, "__mro__" ):
__mro__ = _stdout_default.__mro__
if hasattr( _stdout_default, "__name__" ):
__name__ = _stdout_default.__name__
if hasattr( _stdout_default, "__ne__" ):
__ne__ = _stdout_default.__ne__
if hasattr( _stdout_default, "__new__" ):
__new__ = _stdout_default.__new__
if hasattr( _stdout_default, "__prepare__" ):
__prepare__ = _stdout_default.__prepare__
if hasattr( _stdout_default, "__qualname__" ):
__qualname__ = _stdout_default.__qualname__
if hasattr( _stdout_default, "__reduce__" ):
__reduce__ = _stdout_default.__reduce__
if hasattr( _stdout_default, "__reduce_ex__" ):
__reduce_ex__ = _stdout_default.__reduce_ex__
if hasattr( _stdout_default, "__repr__" ):
__repr__ = _stdout_default.__repr__
if hasattr( _stdout_default, "__setattr__" ):
__setattr__ = _stdout_default.__setattr__
if hasattr( _stdout_default, "__sizeof__" ):
__sizeof__ = _stdout_default.__sizeof__
if hasattr( _stdout_default, "__str__" ):
__str__ = _stdout_default.__str__
if hasattr( _stdout_default, "__subclasscheck__" ):
__subclasscheck__ = _stdout_default.__subclasscheck__
if hasattr( _stdout_default, "__subclasses__" ):
__subclasses__ = _stdout_default.__subclasses__
if hasattr( _stdout_default, "__subclasshook__" ):
__subclasshook__ = _stdout_default.__subclasshook__
if hasattr( _stdout_default, "__text_signature__" ):
__text_signature__ = _stdout_default.__text_signature__
if hasattr( _stdout_default, "__weakrefoffset__" ):
__weakrefoffset__ = _stdout_default.__weakrefoffset__
if hasattr( _stdout_default, "mro" ):
mro = _stdout_default.mro
def __init__(self):
"""
Override any super class `type( _stdout_default )` constructor, so we can
instantiate any kind of `sys.stdout` replacement object, in case it was already
replaced by something else like on Sublime Text with `_LogWriter()`.
Assures all attributes were statically replaced just above. This should happen in case
some new attribute is added to the python language.
This also ignores the only two methods which are not equal, `__init__()` and `__getattribute__()`.
"""
different_methods = ("__init__", "__getattribute__")
attributes_to_check = set( dir( object ) + dir( type ) )
for attribute in attributes_to_check:
if attribute not in different_methods \
and hasattr( _stdout_default, attribute ):
base_class_attribute = super( _stdout_default_class_type, self ).__getattribute__( attribute )
target_class_attribute = _stdout_default.__getattribute__( attribute )
if base_class_attribute != target_class_attribute:
sys.stdout.write( " The base class attribute `%s` is different from the target class:\n%s\n%s\n\n" % (
attribute, base_class_attribute, target_class_attribute ) )
def __getattribute__(self, item):
if item == 'write':
return _sys_stdout_write
try:
return _stdout_default.__getattribute__( item )
except AttributeError:
return super( _stdout_default_class_type, _stdout_default ).__getattribute__( item )
_stdout_singleton = StdOutReplamentHidden()
sys.stdout = _stdout_singleton
return cls
@classmethod
def unlock(cls):
"""
Detach this `stdout` writer from `sys.stdout` and allow the next call to `lock()` create
a new writer for the stdout.
"""
if cls.is_active:
global _sys_stdout_write_hidden
cls.is_active = False
_sys_stdout_write_hidden = _stdout_default.write
要使用此功能,您只需调用StdErrReplament::lock(logger)
并StdOutReplament::lock(logger)
传递要用于发送输出文本的记录器即可。例如:
import os
import sys
import logging
current_folder = os.path.dirname( os.path.realpath( __file__ ) )
log_file_path = os.path.join( current_folder, "my_log_file.txt" )
file_handler = logging.FileHandler( log_file_path, 'a' )
file_handler.formatter = logging.Formatter( "%(asctime)s %(name)s %(levelname)s - %(message)s", "%Y-%m-%d %H:%M:%S" )
log = logging.getLogger( __name__ )
log.setLevel( "DEBUG" )
log.addHandler( file_handler )
log.file_handler = file_handler
log.clean_formatter = logging.Formatter( "", "" )
StdOutReplament.lock( log )
StdErrReplament.lock( log )
log.debug( "I am doing usual logging debug..." )
sys.stderr.write( "Tests 1...\n" )
sys.stdout.write( "Tests 2...\n" )
运行此代码,您将在屏幕上看到:
并在文件内容上:
如果您还希望log.debug
在屏幕上看到呼叫的内容,则需要在记录器中添加流处理程序。在这种情况下,将是这样的:
import os
import sys
import logging
class ContextFilter(logging.Filter):
""" This filter avoids duplicated information to be displayed to the StreamHandler log. """
def filter(self, record):
return not "_duplicated_from_file" in record.__dict__
current_folder = os.path.dirname( os.path.realpath( __file__ ) )
log_file_path = os.path.join( current_folder, "my_log_file.txt" )
stream_handler = logging.StreamHandler()
file_handler = logging.FileHandler( log_file_path, 'a' )
formatter = logging.Formatter( "%(asctime)s %(name)s %(levelname)s - %(message)s", "%Y-%m-%d %H:%M:%S" )
file_handler.formatter = formatter
stream_handler.formatter = formatter
stream_handler.addFilter( ContextFilter() )
log = logging.getLogger( __name__ )
log.setLevel( "DEBUG" )
log.addHandler( file_handler )
log.addHandler( stream_handler )
log.file_handler = file_handler
log.stream_handler = stream_handler
log.clean_formatter = logging.Formatter( "", "" )
StdOutReplament.lock( log )
StdErrReplament.lock( log )
log.debug( "I am doing usual logging debug..." )
sys.stderr.write( "Tests 1...\n" )
sys.stdout.write( "Tests 2...\n" )
运行时将输出如下内容:
虽然它仍然会将其保存到文件中my_log_file.txt
:
当使用禁用此功能时StdErrReplament:unlock()
,它将仅恢复stderr
流的标准行为,因为附加的记录器永远都不会分离,因为其他人可以引用其旧版本。这就是为什么它是永远不会消失的全球单身人士的原因。因此,万一重新加载该模块imp
或其他模块,它将永远不会重新捕获sys.stderr
已注入到模块中的电流并在内部保存它。