Python scope

   Scope of a variable depends on the place, where it is defined and where it is used. Based on this, variables have categorized into following types.

• ·       Local
• ·       Non local
• ·       Global

1. Local variables:

              These are the normal variables that any user use. Let, a variable t is defined inside a function.

Its scope is applicable within the function or file.

Eg:

a = 56

print(a)

Here, a is the local variable. its scope is within this program.

Next, local variable  is defined inside a function is given below.

def  its_fn():

     b = 99

     print(b)

#function call is given below.

its_fn()

while executing this program, you get the below output.

 2.Non local variables.

              When a function is defined inside the other function, this scope is used. Same variable name is used in many functions, the developer wants to differentiate it by the keyword “non local”.

#define a function its_fn() .Declare a variable ‘b’. This is the local variable.

def its_fn():

    b = 99

#Define a function  its_fn1(). Declare a nonlocal b and assign the value. call this function in its_fn() definition and return the value.

    def its_fn1():

        nonlocal b

        b = "Best wishes"

    its_fn1()

    return b

#call the its_fn() and print the value.

print(its_fn())

The output is given below.

Best Wishes

3.Global variable:

              A variable is defined and it can be used anywhere of the program. Here,the keyword is “global”

#Let a variable ‘b’ is assigned with a value 99. It is considered as local variable.

b = 99

#let a function its_fn() is defined. Here, variable ‘b’ is declared as global and assigned with 199.

def its_fn():

    global b

    b = 199

#call the function its_fn()

its_fn()

#print the value of b. it prints the global variable value.

print(b)

So, the output is

 

 These are the various types of variables used in python and its scope is explained with examples.