本文主要介绍了python 动态获取当前运行的类名和函数名的方法，
分别介绍使用内置方法、sys模块、修饰器、inspect模块等方法。
一、使用内置方法和修饰器方法获取类名、函数名
python中获取函数名的情况分为内部、外部
1、从函数外部获取函数名
使用指向函数的对象，然后用__name__属性
defa():
pass
a.__name__
除此之外还可以：
getattr(a,'__name__')
a.__getattribute__('__name__')
完整示例：
def a():
print("hello, l love u")
print(a.__name__)
print(a.__getattribute__('__name__'))
print(getattr(a,'__name__'))
尽管有些脱裤子放屁，总之，从外部获取的方法是非常灵活的。
2、从函数内部获取函数名
需要用些技巧
1）使用sys模块的方法：（推荐）
defa():
printsys._getframe().f_code.co_name
f_code 和 co_name 可以参考python源码解析的pyc生成和命名空间章节。
2）使用修饰器的方法： （推荐）
使用修饰器就可以对函数指向一个变量，然后取变量对象的__name__方法。
deftimeit(func):
defrun(*argv):
printfunc.__name__
ifargv:
ret =func(*argv)
else:
ret =func()
returnret
returnrun
@timeit
deft(a):
printa
t(1)
修饰器的改进版：
使用修饰器就可以对函数指向一个变量，然后取变量对象的__name__方法。
defget_name(func):
defwarper(*args, **kwargs):
print("the function name is {}".format(func.__name__))
result =func(*args, **kwargs)
returnresult
returnwarper
@get_name
defmy_name():
print("hello")
@get_name
defyour_name(name):
print("hello {}".format(name))
my_name()
your_name("mimvp.com")
运行结果：
the function name is my_name
hello
the function name is your_name
hello mimvp.com
二、使用inspect模块动态获取当前运行的函数名
importinspect
defget_current_function_name():
returninspect.stack()[1][3]
classMyClass:
deffunction_one(self):
print"%s.%s invoked"%(self.__class__.__name__, get_current_function_name())
if__name__ =="__main__":
myclass =MyClass()
myclass.function_one()
动态获取当前运行的函数名很方便，特别是对于一些debug系统来说
完整示例：
def timeit(func):
def run(*argv):
print("timeit: %s"% (func.__name__)) # timeit: func
ifargv:
ret = func(*argv)
else:
ret = func()
returnret
returnrun
# @timeit
def func():
print("self name: %s"% (sys._getframe().f_code.co_name)) # self name: func
importinspect
def get_current_function_name():
returninspect.stack()[1][3]
class MyClass:
def function_one(self):
print("%s.%s invoked"% (self.__class__.__name__, get_current_function_name())) # MyClass.function_one invoked
if__name__ == '__main__':
print("%s : __main___"% (__file__.split(MIMVP_PROJECT_NAME)[1])) # /common/mimvptech.py : __main___
print("func.name: %s , getattr(a,'__name__'): %s"% (func.__name__, getattr(func, '__name__'))) # func.name: func , getattr(a,'__name__'): func
func()
myclass = MyClass()
myclass.function_one()
运行结果：
/common/mimvptech.py : __main___
func.name: func , getattr(a,'__name__'): func
self name: func
MyClass.function_one invoked
知识拓展与思考
Python中没办法直接取得当前的行号和函数名，不像C++和PHP中的 __FILE__，__LINE__，__FUNC__，__FUNCTION__
如果一个函数在不知道自己名字的情况下，怎么才能递归调用自己，获取类名、函数名。
从python的logging模块说起，logging中的format中是有如下选项的:
%(name)s Name of the logger (logging channel)
%(levelno)s Numeric logging level forthe message (DEBUG, INFO,
WARNING, ERROR, CRITICAL)
%(levelname)s Text logging level forthe message ("DEBUG", "INFO",
"WARNING", "ERROR", "CRITICAL")
%(pathname)s Full pathname of the source filewhere the logging
call was issued (ifavailable)
%(filename)s Filename portion of pathname
%(module)s Module (name portion of filename)
%(lineno)d Source line number where the logging call was issued
(ifavailable)
%(funcName)s Function name
%(created)f Time when the LogRecord was created (time.time()
returnvalue)
%(asctime)s Textual time when the LogRecord was created
%(msecs)d Millisecond portion of the creation time
%(relativeCreated)d Time inmilliseconds when the LogRecord was created,
relative to the time the logging module was loaded
(typically at application startup time)
%(thread)d Thread ID(ifavailable)
%(threadName)s Thread name (ifavailable)
%(process)d Process ID(ifavailable)
%(message)s The result of record.getMessage(), computed just as
the record isemitted
也就是说，logging是能够获取到调用者的行号和函数名的，那会不会也可以获取到自己的行号和函数名呢？
我们来看一下源码，主要部分如下:
defcurrentframe():
"""Return the frame object for the caller's stack frame."""
try:
raiseException
except:
returnsys.exc_info()[2].tb_frame.f_back
deffindCaller(self):
"""
Find the stack frame of the caller so that we can note the source
file name, line number and function name.
"""
f =currentframe()
#On some versions of IronPython, currentframe() returns None if
#IronPython isn't run with -X:Frames.
iff isnotNone:
f =f.f_back
rv ="(unknown file)", 0, "(unknown function)"
whilehasattr(f, "f_code"):
co =f.f_code
filename =os.path.normcase(co.co_filename)
iffilename ==_srcfile:
f =f.f_back
continue
rv =(co.co_filename, f.f_lineno, co.co_name)
break
returnrv
def_log(self, level, msg, args, exc_info=None, extra=None):
"""
Low-level logging routine which creates a LogRecord and then calls
all the handlers of this logger to handle the record.
"""
if_srcfile:
#IronPython doesn't track Python frames, so findCaller throws an
#exception on some versions of IronPython. We trap it here so that
#IronPython can use logging.
try:
fn, lno, func =self.findCaller()
exceptValueError:
fn, lno, func ="(unknown file)", 0, "(unknown function)"
else:
fn, lno, func ="(unknown file)", 0, "(unknown function)"
ifexc_info:
ifnotisinstance(exc_info, tuple):
exc_info =sys.exc_info()
record =self.makeRecord(self.name, level, fn, lno, msg, args, exc_info, func, extra)
self.handle(record)
简单解释一下，实际上是通过在currentframe函数中抛出一个异常，然后通过向上查找的方式，找到调用的信息。其中
rv = (co.co_filename, f.f_lineno, co.co_name)
上面三个值分别为文件名，行号，函数名。
可以去sys— System-specific parameters and functions来看一下代码中几个系统函数的说明
OK，如果已经看懂了源码，那获取当前位置的行号和函数名相信也非常清楚了，代码如下:
#!/usr/bin/python
# -*- coding: utf-8 -*-
'''
#=============================================================================
# Author: dantezhu - https://www.vimer.cn
# Email: zny2008@gmail.com
# FileName: xf.py
# Description: 获取当前位置的行号和函数名
# Version: 1.0
# LastChange: 2010-12-17 01:19:19
# History:
#=============================================================================
'''
importsys
defget_cur_info():
"""Return the frame object for the caller's stack frame."""
try:
raiseException
except:
f =sys.exc_info()[2].tb_frame.f_back
return(f.f_code.co_name, f.f_lineno)
defcallfunc():
printget_cur_info()
if__name__ =='__main__':
callfunc()
输入结果是:
('callfunc', 24)
符合预期！哈哈，OK！
现在应该不用再抱怨取不到行号和函数名了吧
其实，Python获取函数名、行号，也可以有更简单的方法，如下:
importsys
defget_cur_info():
printsys._getframe().f_code.co_name
printsys._getframe().f_back.f_code.co_name
get_cur_info()
调用结果是:
get_cur_info
另外，利用python的 inspect 模块中的 getframeinfo 也可以得到.
inspect.getframeinfo(frame[,context])
Get information about a frame or traceback object. A 5-tuple is returned, the last five elements of the frame’s frame record.Changed in version 2.6: Returns anamed tupleTraceback(filename, lineno, function,code_context, index).
参考推荐：
Shell 参数含义 $0、$1、$2、${n}、$#、$@、$*、$?、 $_、$!、$$
转载自：https://blog.mimvp.com/article/7218.html
