Python scope

A variable is only available from inside the block of code where it is created. The block is called the scope of the variable.

Local Scope¶

• variable can be accessed inside the block of the code
• if variable created inside function then it can be accessed inside the function only

def square_of_num(num):
    npow = 2
    return 
print(square_of_num(10))
# output: 100

• variable npow can be accessed inside function only otherwise it will throw NameError
• variable npow is called as local variable

Function Inside Function¶

• the local variable can be accessed from a function within the function.
• lets look at the below code

def func():
  x = 300
  def inner():
    return x
  return inner()

output = func()
print(output)
# output: 300

Global Scope¶

• a variable created in the main body of the python code is a global variable and belongs to the global scope.
• global variables are available from within any scope, global and local.

x = 100

def func():
  print(x)

func()
# output: 100
print(x)
# output: 100

Naming Variables¶

• same variable name can be used in both local and global scopes.
• gobal scope varible can't be overridden by the local variable.

name = "Anji"

def change_name():
    name = "Avtar"
    print(name)

change_name()
# output: "Avtar"
print(name)
# output: "Anji"

Global Keyword¶

• global variable value can be udated inside the function by using the global keyword

name = "Anji"

def change_name():
    global name
    name = "Avtar"
    print(name)

change_name()
# output: "Avtar"
print(name)
# output: "Avtar"