Python: Essential Reference, Third Edition

Functions

You use the def statement to create a function, as shown in the following example:

def remainder(a,b):
        q = a // b       # // is truncating division.
        r = a - q*b
        return r

To invoke a function, simply use the name of the function followed by its arguments enclosed in parentheses, such as result = remainder(37,15). You can use a tuple to return multiple values from a function, as shown here:

def divide(a,b):
        q = a // b        # If a and b are integers, q is integer
        r = a - q*b
        return (q,r)

When returning multiple values in a tuple, it’s often useful to invoke the function as follows:

quotient, remainder = divide(1456,33)

To assign a default value to a parameter, use assignment:

def connect(hostname,port,timeout=300):
    # Function body

When default ...