What is the difference between Global variable and Local variable?

Scope of variables

The scopes of the variables depend upon the location where the variable is being declared. The variable declared in one part of the program may not be accessible to the other parts.

In python, the variables are defined with the two types of scopes.

  1. Global variables
  2. Local variables

The variable defined outside any function is known to have a global scope, whereas the variable defined inside a function is known to have a local scope.

Consider the following example.

Example 1 Local Variable

def print_message():    
    message = "hello !! I am going to print a message." # the variable message is local to the function itself    
print(message) # this will cause an error since a local variable cannot be accessible here.      


hello !! I am going to print a message.
  File "/root/PycharmProjects/PythonTest/Test1.py", line 5, in 
NameError: name 'message' is not defined

Example 2 Global Variable

def calculate(*args):    
    for arg in args:    
        sum = sum +arg    
    print("The sum is",sum)    
calculate(10,20,30) #60 will be printed as the sum    
print("Value of sum outside the function:",sum) # 0 will be printed  Output:  


The sum is 60
Value of sum outside the function: 0