How do you call a Variable from Another Function in Python?

Variables :

Variables are used to store values. In simple terms, variables are the values that can vary. You can store any type of data in a variable. The variable is also a part of memory where information is stored. There are some rules for defining a variable in Python. These rules are as follows :

1. The first Character of any variable must be underscored ('_') or a letter (uppercase or lowercase).
2. The rest of the Character after the first Character can be underscore ('_') or letters or digits (0-9).
3. The variable's names are case-sensitive, which means Myvar and myvar are different.
4. Special Characters are not allowed.

There are two ways to call a variable from another function in Python:

1. Global Variables
2. Return Statement

Global Variables:

Global variables are variables that can be used anywhere in the Python program. Global variables allow us to retrieve the values from any function in the program. If a variable is declared globally in one function, it can be accessed in any other function in the whole Python program.

Let's see how to declare a global variable in Python:

Code:

Output:

I am a global variable

Explanation:

In the above code, two functions are declared first_function(), which is used to declare a global variable. The global keyword is used to represent that the variable declared is a global variable and can be used anywhere in the Python program. A value is assigned to the variable 'I am a global variable' that is the global variable. The value of the global variable is printed from the first function. The first function is called, and the global variable is declared. The second function prints the value of the global variable.

Return Statement:

The return statement is an alternative way to call a variable from another function with the help of a return statement. A return statement is a type of statement that helps pass a value from within a function to externally, such as variables.

Let's see an example of accessing the variables from another function in Python:

Code:

Output:

I am a returned variable

Explanation:

In the above code, the function is used to return a value and a statement, 'I am a returned variable,' that is returned. Another second function is used to return the statement from the first function. In the second function a variable is declared to call the first function and the variable is printed and in the last the second function is called to print the variable or return statement of the first function.

How does Function Execution Work in Python?

The function calls are executed in Python with the help of stack data structure. Whenever a function is called, then the function that is called is pushed into a stack, and the calling function is executed. When the execution is complete by the calling function, then the function is popped from the stack and executed, and the value is printed. The function execution is complete only when the called function is completed.

Consider an example:

Code:

Output:

The Sum of the Square of List of Numbers: 385

Explanation:

In the above code, two functions are declared Square and SumofSquares. The sumofSquares function is used to take an array and the length of the array as input, and this function calculates the Sum of the squares of the array. The square is calculated with the square function that returns the square of the number, and the Sum is calculated. The Sum is returned, and the function sum of the square is called by passing the array and the length of the array. The return statement is used to call the variable from the function. The Sum of squares of the list is printed.

With the help class, a variable can be called from another function in the same class, for example.

Code:

Output:

Function2: Hello
Function1: World

Explanation:

In the above code, a main class is created with a constructor. Two strings are made, string1 and string2, initialized with the value "Hello" and "World", respectively. Two methods are created inside the class with the name function1 and function2. Function1 is called function2 and prints the value of string1, and then the print statement prints the value of string2. The object of the class is made, and the method is called for this object.

The variable can be accessed form another function with the help of an inheritance property in the Object Oriented Paradigm.

Here is an example:

Code:

Output:

Function2: Hello
Function1: World

Explanation:

In the above code, a Parent class is made, and two strings are initialized in the constructor method, which is the __init__() method. The values of the strings are Hello and World, respectively. Function2 method is made inside the parent class, and the value of the string is printed. The child class is inherited from the Parent class, and the function1 method is made, the Function2 method is called inside the child class to print the values, and the values of string2 are printed in the child class that is called from the parent class. The object of each class is made, and the function1 method is called from the child class.

Conclusion:

The calling function is the function that calls another function, and the called function is the function that is called by another function.