In Python, how do I get a function name as a string, without calling the function?
def my_function():
pass
print get_function_name_as_string(my_function) # my_function is not in quotes
should output "my_function".
Is such function available in Python? If not, any ideas on how to implement get_function_name_as_string, in Python?
my_function.__name__
Using __name__ is the preferred method as it applies uniformly. Unlike func_name, it works on built-in functions as well:
>>> import time
>>> time.time.func_name
Traceback (most recent call last):
File "<stdin>", line 1, in ?
AttributeError: 'builtin_function_or_method' object has no attribute 'func_name'
>>> time.time.__name__
'time'
Also the double underscores indicate to the reader this is a special attribute. As a bonus, classes and modules have a __name__ attribute too, so you only have remember one special name.
To get the current function's or method's name from inside it, consider:
import inspect
this_function_name = inspect.currentframe().f_code.co_name
sys._getframe also works instead of inspect.currentframe although the latter avoids accessing a private function.
To get the calling function's name instead, consider f_back as in inspect.currentframe().f_back.f_code.co_name.
If also using mypy, it can complain that:
error: Item "None" of "Optional[FrameType]" has no attribute "f_code"
To suppress the above error, consider:
import inspect
import types
from typing import cast
this_function_name = cast(types.FrameType, inspect.currentframe()).f_code.co_name
If you're interested in class methods too, Python 3.3+ has __qualname__ in addition to __name__.
def my_function():
pass
class MyClass(object):
def method(self):
pass
print(my_function.__name__) # gives "my_function"
print(MyClass.method.__name__) # gives "method"
print(my_function.__qualname__) # gives "my_function"
print(MyClass.method.__qualname__) # gives "MyClass.method"
I like using a function decorator. I added a class, which also times the function time. Assume gLog is a standard python logger:
class EnterExitLog():
def __init__(self, funcName):
self.funcName = funcName
def __enter__(self):
gLog.debug('Started: %s' % self.funcName)
self.init_time = datetime.datetime.now()
return self
def __exit__(self, type, value, tb):
gLog.debug('Finished: %s in: %s seconds' % (self.funcName, datetime.datetime.now() - self.init_time))
def func_timer_decorator(func):
def func_wrapper(*args, **kwargs):
with EnterExitLog(func.__name__):
return func(*args, **kwargs)
return func_wrapper
so now all you have to do with your function is decorate it and voila
@func_timer_decorator
def my_func():
As an extension of @Demyn's answer, I created some utility functions which print the current function's name and current function's arguments:
import inspect
import logging
import traceback
def get_function_name():
return traceback.extract_stack(None, 2)[0][2]
def get_function_parameters_and_values():
frame = inspect.currentframe().f_back
args, _, _, values = inspect.getargvalues(frame)
return ([(i, values[i]) for i in args])
def my_func(a, b, c=None):
logging.info('Running ' + get_function_name() + '(' + str(get_function_parameters_and_values()) +')')
pass
logger = logging.getLogger()
handler = logging.StreamHandler()
formatter = logging.Formatter(
'%(asctime)s [%(levelname)s] -> %(message)s')
handler.setFormatter(formatter)
logger.addHandler(handler)
logger.setLevel(logging.INFO)
my_func(1, 3) # 2016-03-25 17:16:06,927 [INFO] -> Running my_func([('a', 1), ('b', 3), ('c', None)])
sys._getframe() is not guaranteed to be available in all implementations of Python (see ref) ,you can use the traceback module to do the same thing, eg.
import traceback
def who_am_i():
stack = traceback.extract_stack()
filename, codeline, funcName, text = stack[-2]
return funcName
A call to stack[-1] will return the current process details.
You just want to get the name of the function here is a simple code for that. let say you have these functions defined
def function1():
print "function1"
def function2():
print "function2"
def function3():
print "function3"
print function1.__name__
the output will be function1
Now let say you have these functions in a list
a = [function1 , function2 , funciton3]
to get the name of the functions
for i in a:
print i.__name__
the output will be
function1
function2
function3
I've seen a few answers that utilized decorators, though I felt a few were a bit verbose. Here's something I use for logging function names as well as their respective input and output values. I've adapted it here to just print the info rather than creating a log file and adapted it to apply to the OP specific example.
def debug(func=None):
def wrapper(*args, **kwargs):
try:
function_name = func.__func__.__qualname__
except:
function_name = func.__qualname__
return func(*args, **kwargs, function_name=function_name)
return wrapper
@debug
def my_function(**kwargs):
print(kwargs)
my_function()
Output:
{'function_name': 'my_function'}
Try
import sys
fn_name = sys._getframe().f_code.co_name
further reference https://www.oreilly.com/library/view/python-cookbook/0596001673/ch14s08.html
