Functions and Parameter Passing/Return Types in Python

Varanasi Software Junction: Python Functions, Parameters and Return Types












"""
Python functions accept input parameters.
Parameters are defined inside the brackets in the function definition.

This function has two parameters.
"""


def add(a, b):
    print("a=", a, ",b=", b)


# Both parameters are necessary
# add(9), add(1,2,3) are errors
"""
Default value parameters

"""


def d1Add(a, b=0):  # b is 0 if not given
    print("a=", a, ",b=", b)


add(1, 2)
d1Add(1, 2)
d1Add(2)  # B is 0


def d2Add(a=0, b=0):
    print("a=", a, ",b=", b)


d2Add(1, 2)
d2Add(1)
d2Add()
d2Add(b=7)  # Using a named parameter


def f1(*args):  # Pass a tuple as parameter
    print(type(args))
    for x in args:
        print(x, end=",")
    print()


def f2(**args):  # Pass a dictionary as parameter
    print(type(args))
    for key in args:
        print(key, "=", args[key], end=",")
    print()


f1(0, 2, 3)
f2(a=1, b=2, c=3)
"""
Return types
Python functions that don't return values explicitly have None
as return value
"""


def r1():  # None as return
    pass


print(r1(), type(r1()))


def r2():  # Int as return
    return 0


print(r2(), type(r2()))


def r3():  # Tuple as return
    return 1, 2


print(r3(), type(r3()))

Output





C:\Users\Lenovo\AppData\Local\Microsoft\WindowsApps\python3.10.exe C:/pythoncodecamp/functions/functionTypes.py
a= 1 ,b= 2
a= 1 ,b= 2
a= 2 ,b= 0
a= 1 ,b= 2
a= 1 ,b= 0
a= 0 ,b= 0
a= 0 ,b= 7
<class 'tuple'>
0,2,3,
<class 'dict'>
a = 1,b = 2,c = 3,
None <class 'NoneType'>
0 <class 'int'>
(1, 2) <class 'tuple'>

Process finished with exit code 0