Python Tutorial

Introduction Python Features Python Applications Python System requirements Python Installation Python Examples Python Basics Python Indentation Python Variables Python Data Types Python IDE Python Keywords Python Operators Python Comments Python Pass Statement

Python Conditional Statements

Python if Statement Python elif Statement Python If-else statement Python Switch Case

Python Loops

Python for loop Python while loop Python Break Statement Python Continue Statement Python Goto Statement

Python Arrays

Python Array Python Matrix

Python Strings

Python Strings Python Regex

Python Built-in Data Structure

Python Lists Python Tuples Python Lists vs Tuples Python Dictionary Python Sets

Python Functions

Python Function Python min() function Python max() function Python User-define Functions Python Built-in Functions Python Recursion Anonymous/Lambda Function in Python apply() function in python Python lambda() Function numpy.divide() in Python

Python File Handling

Python File Handling Python Read CSV Python Write CSV Python Read Excel Python Write Excel Python Read Text File Python Write Text File Read JSON File in Python

Python Exception Handling

Python Exception Handling Python Errors and exceptions Python Assert

Python OOPs Concept

OOPs Concepts in Python Classes & Objects in Python Inheritance in Python Polymorphism in Python Python Encapsulation Python Constructor Python Super function Python Static Method Static Variables in Python Abstraction in Python

Python Iterators

Iterators in Python Yield Statement In Python Python Yield vs Return

Python Generators

Python Generator

Python Decorators

Python Decorator

Python Functions and Methods

Python Built-in Functions Python String Methods Python List Methods Python Dictionary Methods Python Tuple Methods Python Set Methods

Python Modules

Python Modules Python Datetime Module Python Math Module Python Import Module Python Time Module Python Random Module Python Calendar Module CSV Module in Python Python Subprocess Module

Python MySQL

Python MySQL Python MySQL Client Update Operation Delete Operation Database Connection Creating new Database using Python MySQL Creating Tables Performing Transactions Python MySQL Insert Operation

Python MongoDB

Python MongoDB

Python SQLite

Python SQLite

Python Data Structure Implementation

Python Stack Python Queue Python Linked List Python Hash Table Python Graph

Python Advance Topics

Speech Recognition in Python Face Recognition in Python Python Linear regression Python Rest API Python Command Line Arguments Python JSON Python Subprocess Python Virtual Environment Type Casting in Python Python Collections Python Attributes Python Commands Python Data Visualization Python Debugger Python DefaultDict Python Enumerate

Python 2

What is Python 2

Python 3

Anaconda in Python 3 Anaconda python 3 installation for windows 10 List Comprehension in Python3

How to

How to Parse JSON in Python How to Pass a list as an Argument in Python How to Install Numpy in PyCharm How to set up a proxy using selenium in python How to create a login page in python How to make API calls in Python How to run Python code from the command prompt How to read data from com port in python How to Read html page in python How to Substring a String in Python How to Iterate through a Dictionary in Python How to convert integer to float in Python How to reverse a string in Python How to take input in Python How to install Python in Windows How to install Python in Ubuntu How to install PIP in Python How to call a function in Python How to download Python How to comment multiple lines in Python How to create a file in Python How to create a list in Python How to declare array in Python How to clear screen in Python How to convert string to list in Python How to take multiple inputs in Python How to write a program in Python How to compare two strings in Python How to create a dictionary in Python How to create an array in Python How to update Python How to compare two lists in Python How to concatenate two strings in Python How to print pattern in Python How to check data type in python How to slice a list in python How to implement classifiers in Python How To Print Colored Text in Python How to open a file in python How to Open a file in python with Path How to run a Python file in CMD How to change the names of Columns in Python How to Concat two Dataframes in Python How to Iterate a List in Python How to learn python Online How to Make an App with Python How to develop a game in python How to print in same line in python How to create a class in python How to find square root in python How to import numy in python How to import pandas in python How to uninstall python How to upgrade PIP in python How to append a string in python How to comment out a block of code in Python How to change a value of a tuple in Python How to append an Array in Python How to Configure Python Interpreter in Eclipse How to plot a Histogram in Python How to Import Files in Python How to Download all Modules in Python How to get Time in seconds in Python How to Practice Python Programming How to plot multiple linear regression in Python How to set font for Text in Python How to Convert WhatsApp Chat Data into a Word Cloud using Python How to Install Tweepy in Python How to Write a Configuration file in Python How to Install Scikit-Learn How to add 2 lists in Python How to assign values to variables in Python and other languages How to build an Auto Clicker using Python How to check if the dictionary is empty in Python How to check the version of the Python Interpreter How to convert Float to Int in Python How to Convert Int to String in Python How to Define a Function in Python How to Install Pandas in Python How to Plot Graphs Using Python How to Program in Python on Raspberry pi How to Reverse a number in Python How to Sort a String in Python How to build a Virtual Assistant Using Python How to Fix an EOF Error in Python How to make a firewall in Python How to clear screen in Python How to Create User Defined Exceptions in Python How to determine if a binary tree is height-balanced How to Import Kaggle Datasets Directly into Google Colab How to Install Python in Kali Linux How to Generate UUID in Python How to Delete File in Python How to extracting the Decision Rules from the scikit- learn Decision Tree How to Find Median in Python How To Print Space in Python How to Implement Interval Scheduling Algorithm in Python How to Round Off in Python How Can Tensorflow be Used to Download and Explore the Iliad Dataset Using Python How to Add Elements in List in Python How to Install Matplotlib in Python How to Connect Mongodb in Python How to Handle Invalid Arguments with Argparse in Python How to Use the Numpy Sum Function

Sorting

Python Sort List Sort Dictionary in Python Python sort() function Python Bubble Sort

Programs

Factorial Program in Python Prime Number Program in Python Fibonacci Series Program in Python Leap Year Program in Python Palindrome Program in Python Check Palindrome In Python Calculator Program in Python Armstrong Number Program in Python Python Program to add two numbers Anagram Program in Python Number Pattern Programs in Python Even Odd Program in Python GCD Program in Python Python Exit Program Complex Python Programs Python Program to Find Compound Interest Python Program to Find Uncommon Words from Two Strings Python Program to Swap Two Elements in a List Python Program to Perform The Arithmetic Operation Python Program to Count The Number of a Substring in a String Python Program to Print Array Element Present at Even Position Python Program to Print all The Prime Number in an Interval Python Program For Perfect Number

Questions

What is a Script in Python What is the re.sub() function in Python After Python What Should I Learn What Does the Percent Sign (%) Mean in Python What is online python free IDE What is Python online compiler What are the Purposes of Python What is Python compiler GDB What is Ipython shell What does base case mean in recursion What does the if __name__ == "__main__" do in Python What is Sleeping Time in Python What is Collaborative Filtering in ML, Python What is the Python Global Interpreter Lock What is None Literal in Python What is the Output of the bool in Python Why learn Python? Is Python Case-sensitive when Dealing with Identifiers Is Python Case Sensitive Is Python Object Oriented Programming language What is Instance in Python What is re in Python What is PVM in Python What is yield in Python

Differences

Difference between Perl and Python Difference between python list and tuple Difference between Input() and raw_input() functions in Python Difference between Python 2 and Python 3 Difference Between Yield And Return In Python Important Difference between Python 2.x and Python 3.x with Example Difference between Package and Module in Python Difference between Expression and Statement in Python Difference between For Loop and While Loop in Python Difference between Module and Package in Python Difference between Sort and Sorted in Python Difference between Overloading and Overriding in Python Python vs HTML Python vs R Python vs Java Python vs PHP While vs For Loop in Python Python Iterator vs Iterable Set Vs List Python Difference between Dataset from Tensors and Dataset from Tensor Slices

Python Kivy

Kivy Architecture Kivy Buttons Kivy Layouts Kivy Widgets What is Kivy in Python

Python Tkinter

Application to get live USD/INR rate Using Tkinter in Python Application to Search Installed Application using Tkinter in Python Compound Interest GUI Calculator using Tkinter in Python Create a Table Using Tkinter in Python Create First GUI Application using Tkinter in Python File Explorer using Tkinter in Python GUI Calendar using Tkinter in Python GUI to extract lyrics from a song Using Tkinter in Python GUI to Shut down, Restart and Logout from the PC using Tkinter in Python Loan calculator using Tkinter in Python Make Notepad using Tkinter in Python Rank Based Percentile GUI Calculator using Tkinter in Python Screen Rotation app Using Tkinter in Python Spell Corrector GUI using Tkinter in Python Standard GUI Unit Converter using Tkinter in Python Text detection using Tkinter in Python To Do GUI Application using Tkinter in Python Weight Conversion GUI using Tkinter in Python Age calculator using Tkinter Create a Digital Clock Using Tkinter Create a GUI Marksheet using Tkinter Simple GUI Calculator Using Tkinter Simple Registration form using Tkinter Weight Conversion GUI Using Tkinter Color Game Using Tkinter in Python File Explorer in Python using Tkinter Making of Notepad Using Tkinter Python Simple FLAMES Game Using Tkinter Python ToDo GUI Application Using Tkinter Python

Python PyQt5

Compound Interest GUI Calculator using PyQt5 in Python Create Table Using PyQt5 in Python Create the First GUI Application using PyQt5 in Python GUI Calendar using PyQt5 in Python Loan Calculator using PyQt5 in Python Rank Based Percentile GUI Calculator using PyQt5 in Python Simple GUI calculator using PyQt5 in Python Standard GUI Unit Converter using PyQt5 in Python

Misc

Introduction to Scratch programming SKLearn Clustering SKLearn Linear Module Standard Scaler in SKLearn Python Time Library SKLearn Model Selection Standard Scaler in SKLearn Accuracy_score Function in Sklearn Append key Value to Dictionary in Python Cross Entropy in Python Cursor in Python Data Class in Python Imread Python Parameter Passing in Python Program of Cumulative Sum in Python Python Program for Linear Search Python Program to Generate a Random String Read numpy array in Python Scrimba python Sklearn linear Model in Python Scraping data in python Accessing Key-value in Dictionary in Python Find Median of List in Python Linear Regression using Sklearn with Example Problem-solving with algorithm and data structures using Python Python 2.7 data structures Python Variable Scope with Local & Non-local Examples Arguments and parameters in Python Assertion error in python Programs for Printing Pyramid Patterns in Python _name_ in Python Amazon rekognition using python Anaconda python 3.7 download for windows 10 64-bit Android apps for coding in python Augmented reality in python Best app for python Not supported between instances of str and int in python Python comment symbol Python Complex Class Python IDE names Selection Sort Using Python Hypothesis Testing in Python Idle python download for Windows Insertion Sort using Python Merge Sort using Python Python - Binomial Distribution Python Logistic Regression with Sklearn & Scikit Python Random shuffle() method Python variance() function Removing the First Character from the String in Python Adding item to a python dictionary Best books for NLP with Python Best Database for Python Count Number of Keys in Dictionary Python Cross Validation in Sklearn Drop() Function in Python EDA in Python Excel Automation with Python Python Program to Find the gcd of Two Numbers Python Web Development projects Adding a key-value pair to dictionary in Python Python Euclidean Distance Python Filter List Python Fit Transform Python e-book free download Python email utils Python range() Function Python random.seed() function Python PPTX Python Pickle Python Seaborn Python Coroutine Python EOL Python Infinity Python math.cos and math.acos function Python Project Ideas Based On Django Reverse a String in Python Reverse a Number in Python Python Word Tokenizer Python Trigonometric Functions Python try catch exception GUI Calculator in Python Implementing geometric shapes into the game in python Installing Packages in Python Python Try Except Python Sending Email Socket Programming in Python Python CGI Programming Python Data Structures Python abstract class Python Compiler Python K-Means Clustering NSE Tools In Python Operator Module In Python Palindrome In Python Permutations in Python Pillow Python introduction and setup Python Functionalities of Pillow Module Python Argmin Python whois Python JSON Schema Python lock Return Statement In Python Reverse a sentence In Python tell() function in Python Write Dictionary to CSV in Python Write a String in Python Binary Search Visualization using Pygame in Python Latest Project Ideas using Python 2022 Closest Pair of Points in Python ComboBox in Python Best resources to learn Numpy and Pandas in python Check Letter in a String Python Python Console Python Control Statements Convert Float to Int in Python using Pandas Importing Numpy in Pycharm Python Key Error Python NewLine Python tokens and character set Python Strong Number any() Keyword in python Best Database in Python Check whether dir is empty or not in python Comments in the Python Programming Language Convert int to Float in Python using Pandas Decision Tree Classification in Python End Parameter in python __GETITEM__ and __SETITEM__ in Python Python Namespace Python GUI Programming List Assignment Index out of Range in Python List Iteration in Python List Index out of Range Python for Loop List Subtract in Python Python Empty Tuple Python Escape Characters Sentence to python vector Slicing of a String in Python Executing Shell Commands in Python Genetic Algorithm in python Get index of element in array in python Looping through Data Frame in Python Syntax of Map function in Python Python AIOHTTP Alexa Python Artificial intelligence mini projects ideas in python Artificial intelligence mini projects with source code in Python Find whether the given stringnumber is palindrome or not First Unique Character in a String Python Python Network Programming Python Interface Python Multithreading Python Interpreter Data Distribution in python Flutter with tensor flow in python Front end in python Iterate a Dictionary in Python Iterate a Dictionary in Python – Part 2 Allocate a minimum number of pages in python Assertion Errors and Attribute Errors in Python Checking whether a String Contains a Set of Characters in python Python Control Flow Statements *Args and **Kwargs in Python Bar Plot in Python Conditional Expressions in Python Function annotations() in Python Image to Text in python import() Function in Python Import py file in Python Multiple Linear Regression using Python Nested Tuple in Python Python String Negative Indexing Reading a File Line by Line in Python Python Comment Block Base Case in Recursive function python ER diagram of the Bank Management System in python Image to NumPy Arrays in Python NOT IN operator in Python One Liner If-Else Statements in Python Sklearn in Python Cube Root in Python Python Variables, Constants and Literals Creating Web Application in python Notepad++ For Python PyPi TensorFlow Python | Read csv using pandas.read_csv() Run exec python from PHP Python coding platform Python Classification Python | a += b is not always a = a + b PyDev with Python IDE Character Set in Python Best Python AI Projects _dict_ in Python Python Ternary Operators Self in Python Python Modulo Python Packages Python Syntax Python Uses Python Bitwise Operators Python Identifiers Python Matrix Multiplication Python AND Operator Python Logical Operators Python Multiprocessing Python Unit Testing __init__ in Python Advantages of Python Python Boolean Python Call Function Python History Python Image Processing Python main() function Python Permutations and Combinations Conditional Statements in python Confusion Matrix Visualization Python Nested List in Python Python Algorithms Python Modules List Method Overloading in Python Python Arithmetic Operators Assignment Operators in Python Python Division Python exit commands Continue And Pass Statements In Python Colors In Python Convert String Into Int In Python Convert String To Binary In Python Convert Uppercase To Lowercase In Python Convert XML To JSON In Python Converting Set To List In Python Covariance In Python CSV Module In Python Decision Tree In Python Dynamic Typing In Python BOTTLE Python Web Framework Introducing modern python computing in simple packages Reason for Python So Popular Returning Multiple Values in Python Spotify API in Python Spyder (32-bit) - Free download Time. Sleep() in Python Traverse Dictionary in Python YOLO Python Nested for Loop in Python Data Structures and Algorithms Using Python | Part 1 Data Structures and Algorithms using Python | Part 2 ModuleNotFoundError No module named 'mysql' in Python N2 in Python XGBoost for Regression in Python Explain sklearn clustering in Python Data Drop in Python Falcon Python Flutter Python Google Python Class Excel to CSV in Python Google Chrome API in Python Gaussian elimination in python Matrix List Comprehension in Python Python List Size Python data science course StandardScaler in Sklearn Python Redis Example Python Program for Tower of Hanoi Python Printf Style Formating Python Percentage Sign Python Parse Text File Python Parallel Processing Python Online Compiler Python maketrans() function Python Loop through a Dictionary Python for Data Analysis Python for Loop Increment Python Kwargs Example Python Line Break Kite Python Length of Tuple in Python Python String Lowercase Python Struct Python Support Python String Variable Python System Command Python TCP Server Python Unit Test Cheat String Python Validator Unicode to String in Python An Introduction to Mocking in Python An Introduction to Subprocess in Python with Examples Anytree Python API Requests using Python App Config Python Check if the directory exists in Python Managing Multiple Python Versions With pyenv os.rename() method in Python os.stat() method in Python Python Ways to find nth occurrence of substring in a string Python Breakpoint Find Last Occurrence of Substring using Python Python Operators Python Selectors Python Slice from Last Occurrence of K Sentiment Analysis using NLTK String indices must be integers in Python Tensorflow Angular in Python AES CTR Python Crash Course on Python by Google Curdir Python Exrex Python FOO in Python Get Bounding Box Co-ordinates Python Hog Descriptor Opencv Python Io stringio Python iobase Python IPython Display Iterate through the list in Python Joint Plot in Python JWT Decode Python List Comprehension in Python List in Python Map Syntax in Python Python Marshmallow PyShark in Python Python Banner Python Logging Maxbytes Python Multiprocessing Processor Python Skyline Python Subprocess Call Example Python Sys Stdout Python Win32 Process Python's Qstandarditemmodel Struct Module in Python Sys Module in Python Tuple in Python Uint8 Python XXhash Python Examples XXhash Python Handling missing keys in Python dictionaries Python Num2words Python Os sep OSError in Python Periodogram in Python Pltpcolor in Python Poolmanager in Python Python pycountry Python pynmea2 Add a key-value pair to dictionary in Python Add Dictionary to Dictionary in Python Add Element to Tuple in Python Add in Dictionary Python Arithmetic Expressions in Python Array to String in Python AX Contour in Python Best Way to Learn Python for Free Captcha Code in Python with Example CatPlot in Python Change Data Type in Python Check if a String is Empty in Python Algorithm for Factorial of a number in Python chr() and ord() Functions in Python Class and Static Methods in Python Convert List to Array in Python Copying a file from one folder to Another with Python Cx_Oracle Python with Example Enumerate() Function in Python Event Key in Python Exclusive OR in Python Exponentiation in Python Expressions in Python Filter List in Python Find key from value in dictionary python Find Words in String Python First unique character in a string Python Fsolve in Python GET and POST requests using Python Gethostbyname() function in Python Comment starts with the symbol in Python Isodate Python Isreal() Python Mrcnn Python OS Module in Python Paramiko Python Example Python BytesIO Python Deep Copy and Shallow Copy Python Glob Python Memory Management Python Operator Precedence Python Parser Python Project Ideas Python sklearn train_test_split Python SymPy Python Syntax Error Invalid Syntax Python Tricks: The Book Sort a dataframe based on a column in Python Spark and Python for big data with pyspark github Standard Scalar in Python STL in Python Sublime Python Sum of Prime Numbers in Python XML parsing in Python The ZEN of Python THONNY IDE Tic Tac Toe Python Tweepy Python Types of Functions in Python Virtualenv Python3 Python Visual Studio Z Pattern in Python Aggregation data across one or more columns Boolean Literals in Python Find() Function in Python Heap Sort in Python .iloc function in Python Integers and floating-point numbers in Python Label and Integer-based Slicing Technique in Python ML Cancer Cell Classification Using Scikit-learn Mutable and Immutable Data Types in Python PEMDAS in Python Precedence Order In Python Product of Two Numbers in Python Python Built-in Exceptions Python Decorator Wraps Python dedent Python deep copy object Python deep learning library Python def Python duplicate list Python Hashlib Python Introduction Notes Python is Easy to Learn or Not Python list files in Directory Python Long Int Python Loop Questions Python Program to find the Largest Number in a List Python Programming Practice Questions Python Raise an Exception Reduce Function in Python Reverse a Tuple in Python Reverse of Array in Python Sieve of Eratosthenes in Python Special Literals in Python String to Int in Python 3 Temperature Conversion Program in Python Two Conditions in If Statement Python Types of Knapsack Problems in Python XOR Function in Python Best First Search Program in Python Binary to Decimal Conversion in Python Environment Variables in Python Escape Sequence Characters in Python Export WhatsApp Chat History to Excel using Python Fizzbuzz Program in Python Float in Python fromtimestamp() function of Datetime.date class in Python Get Random Dog Images in Python Handling EOFError Exception in Python Python Delete Folder and Contents Python Expanduser Python gdb Breakpoint Remove special characters from string in Python DRF Serializer in Python Logistic Regression in Python Python del multiple variables Python Delete a Directory with Files Python Delete Files from Directory Python Delete Key Types of Functions in Python Understanding Variable Length Arguments in Python XOR in Python Compound Interest Program in Python Python Linear Algebra Python Static Method Python Socket Server String Manipulation in Python Python Virtualenv Create Create Virtual Environment in Python Python threading thread Latest Project Ideas using Python 2023 json.load() in Python Python module PySimpleGUI Send Mail with Attachments from your Gmail Account using Python Visualizing O full completed in Python Visualizing Quick Sort using Tkinter in Python Send PDF files through email using PDF Mail Modules in Python Visualizing Bubble Sort using Tkinter in Python Python Cvtcolor Get all keys from directory Python Import JSON file in Python io BytesIO Python json.dumps() function in Python Kruskal’s Algorithm in Python Null in Python Online Python Compiler PyDev in Python Python Database Tutorial Python Garbage Collection Python Hashmap Python Private Method Python Projects for Beginners Python Subprocess Run Python Threading Timer Operator Overloading in Python Pointers in Python Python Not Equal Operator Raise Exception in Python Salary of Python Developers in India Decision Tree Regression using Sklearn in Python Python Visualizing images in different Color Spaces Visualizing Geospatial Data using Folium in Python Agglomerative Clustering with and without Structure in Scikit-Learn Top 10 Python Built-In Decorators that Optimize Python Code Significantly Python Competitive Programming Questions Sum of two Columns in OpenPyxl and Result in a new Column Python Degree Symbol 10 Useful Python One Liners that Developers Must Know Building a File Encryption in C to Secure Sensitive Data Clustering Text Documents Using K Means in Scikit Learn Creating a Basic Operating System Simulator in C to Understand Process Management Developing a Web Scraper Using Python to Extract Data from Websites Filter Pandas Dataframe in Python Using in and Not in Get N Smallest Values from a Particular Column K Means Clustering On the Handwritten Digits Data Using Scikit Learn in Python Python for Natural Language Processing analyzing Text Data Text to Speech by Using TTSvoice Textwrap Text Wrapping and Filling in Python Top 10 Python Libraries for Cyber Security Implementing Artificial Neural Network Training Process in Python Mini Batch Gradient Descent With Python Gaussian Process Classification on the Xor Dataset in Scikit Learn Indentation Error in Python Morse Code Translator in Python Shorthand Shortcut Compound Assignment Operators in Python Load and Dump in Python Longest Common Substring in Python Priority Queue in Python Python List Files in a Directory Recursively Prior and Posterior Gaussian Process for Different Kernels in Scikit Learn Structured Vs Unstructured Ward in Hierarchical Clustering Using Scikit Learn Tensorflow TF Data Dataset from Tensor Slices Advantages and Disadvantages of Sorting Algorithms Arguments of Print in Python Characteristics of Algorithm in Python Language Translator Using Google Api in Python Python Binary Tree Python Files I O Python Global Keyword Python Planck Discrete Distribution in Statistics Python Remove Stopwords Python Removes an Element From the List Python Not Equal Operator and Ne Magic Method Python Statistical Module Wxpython Panel Class Design a Keylogger in Python Find the Series Containing Counts of Unique Values using Index.value_counts() Garbage Collection in Python Heap Data Structure in Python Iconphoto Method in Tkinter Using Python Implement Phonetic Search in Python with Soundex Algorithm KMP Algorithm for Pattern Searching Using Python Levy Stable Distribution in Statistics Using Python Optimized Algorithm for Pattern Searching Using Python Python Poisson Discrete Distribution in Statistics Python Appium Framework Rabin Karp Algorithm for Pattern Searching Using Python Trie Data Structure in Python Unbiased Standard Error of the Mean Vertical Concatenation in Matrix Using Python

Python lambda() Function

In this tutorial, we will learn about a new concept known as the Lambda function. It is a relatively new concept while learning Python.

Python lambda functions are anonymous functions. It means that a function is without a name. Any function in python is defined using the ‘def’ keyword. Similarly, a lambda function is defined using a ‘lambda’ keyword for defining the anonymous functions.

Syntax

The syntax for creating a lambda function is:

lambda arguments: expression

Properties

  • Python lambda function can have any number of arguments, but it will only have one expression. That expression is later on evaluated and returned.
  • Anyone can use the lambda function whenever an object function is required.
  • We should always remember that lambda functions are syntactically restricted to one expression only.

Example of Lambda Function

Let’s understand with an example of the lambda function.

# Program to show the use of lambda functions
double = lambda x: x * 10


print(double(2))

Output

20

Explanation

In the above program, we have used the lambda function using the lambda keyword and an expression. lambda x: x*10 is a lambda function. In this lambda function, x is the argument, and  x*10 is an expression. This expression is evaluated and returned. The function has no name and returns a function object assigned to the identifier double.  We can call it a normal function.

double = lambda x: x * 10

can also be written as

def double(x):
    return x * 10;

Difference between Lambda function and def function

Using an example, let’s understand the difference between the lambda function and a def function. This program will return the square of a number.

Code:

def  square(y):
    return y*y
  
lambda_square = lambda y: y*y
  
# using the normally
# defined function
print(square(5))
  
# using the lambda function
print(lambda_square(5))

Output

25
25

Explanation

As you can see, both functions square() and lambda_square()are doing the same thing. They both give an output of the square of the numbers passed as argument. When we use a function, we have to pass a value to the function defined using the def keyword. In this function, we have to give a name to the function. After evaluating the value, we can return the value to where the function was called using the return keyword.

While we use the lambda function, we don’t have to use the return statement. It always returns an evaluated and returned expression without using any return keyword. We can also put the lambda expression anywhere in the code, and we don’t have to assign it to a variable. This is how we can use a lambda function.

Using of Lambda function with list comprehension

y = [lambda x=x: x*2 for x in range(1, 11)]
  
for table in y:
    print(table())

Output

2
4
6
8
10
12
14
16
18
20

Explanation

In the above code, we have used the lambda function with a list comprehension. This program will print the table of two from range 1 to 10. In this program, we have used x as an argument and x*2 as an expression. This expression will get evaluated and returned, and get printed.

Use of lambda function

We use lambda functions mostly when we want a nameless function for a short period. In python, lambda functions are used as an argument for other higher-order functions. Higher-order functions are those functions that take another function as an argument. There are two built-in functions along with which we use lambda functions: map () and filter().

Use with filter( )

Example

# Program to filter out only the odd items from a list
list_val = [1, 5, 4, 6, 8, 11, 3, 12]


list1 = list(filter(lambda x: (x%2 != 0) , list_val))


print(list1)

Output

[1, 5, 11, 3]

Explanation

We used the filter() function in the above code to return the odd numbers from the list. This function takes the lambda function as an argument and the list. After evaluating the expression (x%2 !=0), we will return the value and print the list.

Use of map()

Example

# Program to double each item in a list using map()


list1 = [1, 5, 4, 6, 8, 11, 3, 12]


my_list = list(map(lambda x: x * 2 , list1))


print(my_list)

Output

[2, 10, 8, 12, 16, 22, 6, 24]

Explanation

In the above code, we have the map() function to double all the elements of the list. In the map() function, we have passed the lambda function and the list as an argument, and after that, when the expression( x*2) is evaluated, we return the value.