The special attribute __name__
of a function, class or module is a string containing its name.
import os
class C:
pass
def f(x):
x += 2
return x
print(f)
# <function f at 0x029976B0>
print(f.__name__)
# f
print(C)
# <class '__main__.C'>
print(C.__name__)
# C
print(os)
# <module 'os' from '/spam/eggs/'>
print(os.__name__)
# os
The __name__
attribute is not, however, the name of the variable which references the class, method or function, rather it is the name given to it when defined.
def f():
pass
print(f.__name__)
# f - as expected
g = f
print(g.__name__)
# f - even though the variable is named g, the function is still named f
This can be used, among others, for debugging:
def enter_exit_info(func):
def wrapper(*arg, **kw):
print '-- entering', func.__name__
res = func(*arg, **kw)
print '-- exiting', func.__name__
return res
return wrapper
@enter_exit_info
def f(x):
print 'In:', x
res = x + 2
print 'Out:', res
return res
a = f(2)
# Outputs:
# -- entering f
# In: 2
# Out: 4
# -- exiting f