how to use arguments in python code example

Example 1: pass argument to a py file

import sys

def hello(a,b):
    print "hello and that's your sum:", a + b

if __name__ == "__main__":
    a = int(sys.argv[1])
    b = int(sys.argv[2])
    hello(a, b)
# If you type : py main.py 1 5
# It should give you "hello and that's your sum:6"

Example 2: python read arguments

#!/usr/bin/python

import sys

print('Number of arguments:', len(sys.argv), 'arguments.')
print('Argument List:', str(sys.argv))

Example 3: read argument from terminal

#!/usr/bin/python

import sys

print 'Number of arguments:', len(sys.argv), 'arguments.'
print 'Argument List:', str(sys.argv)

#Terminal
# $ python test.py arg1 arg2 arg3

#print
#Number of arguments: 4 arguments.
#Argument List: ['test.py', 'arg1', 'arg2', 'arg3']

Example 4: python arguments

import sys

print ("the script has the name %s" % (sys.argv[0])

Example 5: python function arguments

#*args and **kwargs are normally used as arguments when calling the function.

#*args returns as tuple and **kwargs returns as dictionary.

#*args and **kwargs  let you write functions with variable number of arguments in python.

def func(required,*args,**kwargs):
    return f"{required} {args} {kwargs}"
  
func("Nagendra",5,32,2,1,23,) #output == 'Nagendra (5, 32, 2, 1, 23) {}'
func("Nagendra",5,32,2,1,23,key1="55",key2="75") #output == "Nagendra (5, 32, 2, 1, 23) {'key1': '55', 'key2': '75'}"

#Very understable example of args.
#Given n number of arguments in a function calculate its average
def average(*args):
  '''
  As we already know *args means collection of values in a tuple.
  INPUT: arguments are given. example average(4,10,) 
  OUTPUT: average of two numbers (4+10)/2 == 14
  '''
  return sum(args)/len(args)

average(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15) #output == 8.0