How can I read a function's signature including default argument values?

python arguments inspect
Spì picture Spì · Apr 20, 2010 · Viewed 71.4k times · Source

Given a function object, how can I get its signature? For example, for:

def myMethod(firt, second, third='something'):
    pass

I would like to get "myMethod(firt, second, third='something')".

Answer

unutbu picture unutbu · Apr 20, 2010 
import inspect

def foo(a, b, x='blah'):
    pass

print(inspect.getargspec(foo))
# ArgSpec(args=['a', 'b', 'x'], varargs=None, keywords=None, defaults=('blah',))

However, note that inspect.getargspec() is deprecated since Python 3.0.

Python 3.0--3.4 recommends inspect.getfullargspec().

Python 3.5+ recommends inspect.signature().

Related questions

Print multiple arguments in Python

This is just a snippet of my code: print("Total score for %s is %s ", name, score) But I want it to print out: "Total score for (name) is (score)" where name is a variable in a list and score …

Read More
TypeError: method() takes 1 positional argument but 2 were given

If I have a class... class MyClass: def method(arg): print(arg) ...which I use to create an object... my_object = MyClass() ...on which I call method("foo") like so... >>> my_object.method("foo") Traceback (most recent …

Read More
How do I create a Python function with optional arguments?

I have a Python function which takes several arguments. Some of these arguments could be omitted in some scenarios. def some_function (self, a, b, c, d = None, e = None, f = None, g = None, h = None): #code The arguments d …

Read More