Python - Functions

Functions in Python

A function is a block of code that runs only when it is called. We can pass parameters to the function, perform an operation on it, and return the result.

Types of Function

There are two types of functions in Python:

  1. Built-In function: Predefined in Python (len(), print(), sum(), etc.)
  2. User-defined function: Created by programmers for individual tasks.

How to define a function in Python?

In Python, we can define a function using the 'def' keyword. When declaring a function in Python, the 'def' keyword must come first, then the function name, any parameters in parenthesis, and then a colon. The code that needs to be run is indented in the function body. The 'return' statement is optional for a function to return a value.

Let's see the below code how we can define the function in Python:



def function_name(#parameters):
    # code logic
    print("print the statement")

Calling a Function

To call a function in Python, use the function_name followed by parenthesis:

# call the function
function_name()

Example

In the following example, we demonstrate the use of function in Python:

def function_name():
    name = "letsupdateskills"
    print(name)

# call the function
function_name() # output: letsupdateskills

Function Return Value

A function's return value is the value that a function returns when it completes its task. The type of value a function returns depends on the task that it performs. For example, a function can return a value like an integer, object, or string.

To return a value from a function, you must include a return statement, the value to be returned, which must precede the last statement of the function.

Example

In this example, we define a function that calculates the sum of two numbers and uses the return statement to return the sum.

def sum(a, b):
    sum_of_number = a + b
    # return statement
    return sum_of_number
ans = sum(10, 20)
print(ans) # output: 30

Function Argument

Function arguments are the values that are passed to a function when it is called. They are specified within the parentheses after the function name.

Example

Let's define the function argument in the following example:

def greet(name, age):
  print(f"Hello, {name}! You are {age} years old.")
greet("Aman", 25)  # Output: Hello, Aman! You are 25 years old.

In the above example, name and age are the arguments of the function greet. When calling the function you can pass the value of this argument.

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Python

Beginner 5 Hours

Functions in Python

A function is a block of code that runs only when it is called. We can pass parameters to the function, perform an operation on it, and return the result.

Types of Function

There are two types of functions in Python:

  1. Built-In function: Predefined in Python (len(), print(), sum(), etc.)
  2. User-defined function: Created by programmers for individual tasks.

How to define a function in Python?

In Python, we can define a function using the 'def' keyword. When declaring a function in Python, the 'def' keyword must come first, then the function name, any parameters in parenthesis, and then a colon. The code that needs to be run is indented in the function body. The 'return' statement is optional for a function to return a value.

Let's see the below code how we can define the function in Python:


python

python
def function_name(#parameters): # code logic print("print the statement")
python

Calling a Function

To call a function in Python, use the function_name followed by parenthesis:

python
# call the function function_name()

Example

In the following example, we demonstrate the use of function in Python:

python
def function_name(): name = "letsupdateskills" print(name) # call the function function_name() # output: letsupdateskills

Function Return Value

A function's return value is the value that a function returns when it completes its task. The type of value a function returns depends on the task that it performs. For example, a function can return a value like an integer, object, or string.

To return a value from a function, you must include a return statement, the value to be returned, which must precede the last statement of the function.

Example

In this example, we define a function that calculates the sum of two numbers and uses the return statement to return the sum.

python
def sum(a, b): sum_of_number = a + b # return statement return sum_of_number ans = sum(10, 20) print(ans) # output: 30

Function Argument

Function arguments are the values that are passed to a function when it is called. They are specified within the parentheses after the function name.

Example

Let's define the function argument in the following example:

python
def greet(name, age): print(f"Hello, {name}! You are {age} years old.") greet("Aman", 25) # Output: Hello, Aman! You are 25 years old.

In the above example, name and age are the arguments of the function greet. When calling the function you can pass the value of this argument.

Frequently Asked Questions for Python

Python is commonly used for developing websites and software, task automation, data analysis, and data visualisation. Since it's relatively easy to learn, Python has been adopted by many non-programmers, such as accountants and scientists, for a variety of everyday tasks, like organising finances.


Python's syntax is a lot closer to English and so it is easier to read and write, making it the simplest type of code to learn how to write and develop with. The readability of C++ code is weak in comparison and it is known as being a language that is a lot harder to get to grips with.

Learning Curve: Python is generally considered easier to learn for beginners due to its simplicity, while Java is more complex but provides a deeper understanding of how programming works. Performance: Java has a higher performance than Python due to its static typing and optimization by the Java Virtual Machine (JVM).

Python can be considered beginner-friendly, as it is a programming language that prioritizes readability, making it easier to understand and use. Its syntax has similarities with the English language, making it easy for novice programmers to leap into the world of development.

To start coding in Python, you need to install Python and set up your development environment. You can download Python from the official website, use Anaconda Python, or start with DataLab to get started with Python in your browser.

Learning Curve: Python is generally considered easier to learn for beginners due to its simplicity, while Java is more complex but provides a deeper understanding of how programming works.

Python alone isn't going to get you a job unless you are extremely good at it. Not that you shouldn't learn it: it's a great skill to have since python can pretty much do anything and coding it is fast and easy. It's also a great first programming language according to lots of programmers.

The point is that Java is more complicated to learn than Python. It doesn't matter the order. You will have to do some things in Java that you don't in Python. The general programming skills you learn from using either language will transfer to another.


Read on for tips on how to maximize your learning. In general, it takes around two to six months to learn the fundamentals of Python. But you can learn enough to write your first short program in a matter of minutes. Developing mastery of Python's vast array of libraries can take months or years.


6 Top Tips for Learning Python

  • Choose Your Focus. Python is a versatile language with a wide range of applications, from web development and data analysis to machine learning and artificial intelligence.
  • Practice regularly.
  • Work on real projects.
  • Join a community.
  • Don't rush.
  • Keep iterating.

The following is a step-by-step guide for beginners interested in learning Python using Windows.

  • Set up your development environment.
  • Install Python.
  • Install Visual Studio Code.
  • Install Git (optional)
  • Hello World tutorial for some Python basics.
  • Hello World tutorial for using Python with VS Code.

Best YouTube Channels to Learn Python

  • Corey Schafer.
  • sentdex.
  • Real Python.
  • Clever Programmer.
  • CS Dojo (YK)
  • Programming with Mosh.
  • Tech With Tim.
  • Traversy Media.

Python can be written on any computer or device that has a Python interpreter installed, including desktop computers, servers, tablets, and even smartphones. However, a laptop or desktop computer is often the most convenient and efficient option for coding due to its larger screen, keyboard, and mouse.

Write your first Python programStart by writing a simple Python program, such as a classic "Hello, World!" script. This process will help you understand the syntax and structure of Python code.

  • Google's Python Class.
  • Microsoft's Introduction to Python Course.
  • Introduction to Python Programming by Udemy.
  • Learn Python - Full Course for Beginners by freeCodeCamp.
  • Learn Python 3 From Scratch by Educative.
  • Python for Everybody by Coursera.
  • Learn Python 2 by Codecademy.

  • Understand why you're learning Python. Firstly, it's important to figure out your motivations for wanting to learn Python.
  • Get started with the Python basics.
  • Master intermediate Python concepts.
  • Learn by doing.
  • Build a portfolio of projects.
  • Keep challenging yourself.

Top 5 Python Certifications - Best of 2024
  • PCEP (Certified Entry-level Python Programmer)
  • PCAP (Certified Associate in Python Programmer)
  • PCPP1 & PCPP2 (Certified Professional in Python Programming 1 & 2)
  • Certified Expert in Python Programming (CEPP)
  • Introduction to Programming Using Python by Microsoft.

The average salary for Python Developer is ₹5,55,000 per year in the India. The average additional cash compensation for a Python Developer is within a range from ₹3,000 - ₹1,20,000.

The Python interpreter and the extensive standard library are freely available in source or binary form for all major platforms from the Python website, https://www.python.org/, and may be freely distributed.

If you're looking for a lucrative and in-demand career path, you can't go wrong with Python. As one of the fastest-growing programming languages in the world, Python is an essential tool for businesses of all sizes and industries. Python is one of the most popular programming languages in the world today.

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