[Tutor] How to make def where arguments are either stated when called or entered via raw_input

[David Craig]

Hi,
I'm trying to write a function that will either take arguments when the 
function is called, such as myFunc(x,y,z) or if the user does not enter 
any arguments, myFunc() the raw_input function will ask for them. But I 
dont know how to check how many arguments have been entered. My code is 
below. Anyone know how??
Thanks
D


def NoiseCorr(file1,file2,500,0.25,0.35):

#######################################################################################
### Check number of arguments
     ??????????????????

#######################################################################################
### User inputs.
     if numArgs == 0:
        file1 = raw_input('Path to Station 1: ')
        file2 = raw_input('Path to Station 2: ')
        shift_length = raw_input('Length of Correlation: ')
        freqMin = raw_input('Min. Frequency: ')
        freqMax = raw_input('Max. Frequency: ')