In Python, you can used named arguments. This is useful when functions have lots of parameters and you want to know which arguments mean what, and also when you are using default arguments.

In [1]:
def f(a = 1, b = 2, c = 3):
    return a + b + c

You can provide any of the arguments you want, and leave out others, if you name the arguments like this:

In [2]:
f(b = 5) #1 + 5 + 2
Out[2]:
9
In [3]:
f(b = 5, a = 10)  #10 + 5 + 3
Out[3]:
18

The function doesn't have to have default parameters:

In [4]:
def g(a, b, c):
    return a*b*c
In [5]:
g(a=1, b=2, c=10)
Out[5]:
20