Introspection for functions/methods using inspect modules

func_introspection.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import inspect

def func1(arg1, arg2, arg3):
    pass

def func2(arg1, arg2, arg3='arg3_default'):
    pass

def func3(arg1, arg2='arg2_default', arg3='arg3_default', *args, **kwargs):
    pass

def describe_func(func):
    print "Name:", func.func_name
    print "Code:"
    print inspect.getsource(func)
    argspec = inspect.getargspec(func)
    describe_args(argspec)
    print "--"
    print

def describe_args(argspec):
    args_with_defaults = argspec.defaults or []

    num_fixed_args = len(argspec.args)
    num_fixed_args_with_defaults = len(args_with_defaults)
    num_fixed_args_without_defaults = num_fixed_args - num_fixed_args_with_defaults
    
    print "Named args (without defaults)", argspec.args[:num_fixed_args_without_defaults]
    if argspec.defaults:
       args_with_default = argspec.args[len(argspec.args)-len(argspec.defaults):]
       print "Named args with default", args_with_default
       for index,arg in enumerate(args_with_default):
           print "\tArg name: %s, default = %s" % (arg, str(argspec.defaults[index]))

    print "Varargs param:", argspec.varargs or 'Not defined'
    print "keywords param:", argspec.keywords or 'Not defined'
    

class Class1(object):
    def method1(self, arg1, arg2='value2'):
        pass

describe_func(func1)
describe_func(func2)
describe_func(func3)

obj1 = Class1()
describe_func(obj1.method1)

func_introspection_output.txt

Name: func1
Code:
def func1(arg1, arg2, arg3):
    pass

Named args (without defaults) ['arg1', 'arg2', 'arg3']
Varargs param: Not defined
keywords param: Not defined
--

Name: func2
Code:
def func2(arg1, arg2, arg3='arg3_default'):
    pass

Named args (without defaults) ['arg1', 'arg2']
Named args with default ['arg3']
        Arg name: arg3, default = arg3_default
Varargs param: Not defined
keywords param: Not defined
--

Name: func3
Code:
def func3(arg1, arg2='arg2_default', arg3='arg3_default', *args, **kwargs):
    pass

Named args (without defaults) ['arg1']
Named args with default ['arg2', 'arg3']
        Arg name: arg2, default = arg2_default
        Arg name: arg3, default = arg3_default
Varargs param: args
keywords param: kwargs
--

Name: method1
Code:
    def method1(self, arg1, arg2='value2'):
        pass

Named args (without defaults) ['self', 'arg1']
Named args with default ['arg2']
        Arg name: arg2, default = value2
Varargs param: Not defined
keywords param: Not defined
--