Check the number of parameters passed in Python function

Question

I\'m new in Python and wants to know if there is a simple way to get amount of passed parameters in Python function.

a(1, 2, 3) ==>3
a(1, 2) ==>2


        

Answer 1

def a(*args, **kwargs):
  print(len(args) + len(kwargs))

Answer 2

You can do this by using locals()

It is important to note, that this should be done as ultimately, your first step in your method. If you introduce a new variable in your method, you will change your results. So make sure you follow it this way:

def a(a, b, c):
    # make this your first statement
    print(len(locals()))

If you did this:

def a(a, b, c):
    z = 5
    print(len(locals()))

You would end up getting 4, which would not be right for your expected results.

Documentation on locals()

Answer 3

you could also change the input for your function to a list, so to have a function:

a(your_list)

then to know how many arguments have been passed to the function, you could simply do:

print len(your_list)

However, this means that you change the input type for your function, from many input variables to only one, the list(which can have a variable number of elements).