代码如下：
############################
# 以下是 @deprecated 装饰器
#
# 该装饰器可以带一个函数废止原因，也可以不带，用法：
# 带原因用法
# @deprecated("please, use another function")
# def old_function(x, y):
# pass
#
# 不带原因用法：
# @deprecated
# def old_function(x, y):
# pass
###############################
import functools
import inspect
import warnings
string_types = (type(b''), type(u''))
def deprecated(reason):
"""
This is a decorator which can be used to mark functions
as deprecated. It will result in a warning being emitted
when the function is used.
"""
if isinstance(reason, string_types):
# The @deprecated is used with a 'reason'.
#
# .. code-block:: python
#
# @deprecated("please, use another function")
# def old_function(x, y):
# pass
def decorator(func1):
if inspect.isclass(func1):
fmt1 = "Call to deprecated class {name} ({reason})."
else:
fmt1 = "Call to deprecated function {name} ({reason})."
@functools.wraps(func1)
def new_func1(*args, **kwargs):
warnings.simplefilter('always', DeprecationWarning)
warnings.warn(
fmt1.format(name=func1.__name__, reason=reason),
category=DeprecationWarning,
stacklevel=2
)
warnings.simplefilter('default', DeprecationWarning)
return func1(*args, **kwargs)
return new_func1
return decorator
elif inspect.isclass(reason) or inspect.isfunction(reason):
# The @deprecated is used without any 'reason'.
#
# .. code-block:: python
#
# @deprecated
# def old_function(x, y):
# pass
func2 = reason
if inspect.isclass(func2):
fmt2 = "Call to deprecated class {name}."
else:
fmt2 = "Call to deprecated function {name}."
@functools.wraps(func2)
def new_func2(*args, **kwargs):
warnings.simplefilter('always', DeprecationWarning)
warnings.warn(
fmt2.format(name=func2.__name__),
category=DeprecationWarning,
stacklevel=2
)
warnings.simplefilter('default', DeprecationWarning)
return func2(*args, **kwargs)
return new_func2
else:
raise TypeError(repr(type(reason)))
