Lambda Expression in Python

Lambda functions in Python are small anonymous functions defined using the lambda keyword. They are commonly used for short, simple operations where defining a full function using def is unnecessary.

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What is a Lambda Function?

A Lambda function is a one-line function without a name. It can take multiple arguments but can contain only one expression.

Syntax:

lambda arguments: expression

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Basic Example

# Normal function
def add(a, b):
    return a + b

print(add(5, 3))

Using Lambda

add = lambda a, b: a + b
print(add(5, 3))

The Lambda version is shorter and cleaner for simple logic.

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Lambda with Single Argument

square = lambda x: x * x
print(square(4))

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Lambda with Multiple Arguments

multiply = lambda x, y, z: x * y * z
print(multiply(2, 3, 4))

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Using Lambda with Built-in Functions

1. map()

numbers = [1, 2, 3, 4]
squares = list(map(lambda x: x * x, numbers))
print(squares)

2. filter()

numbers = [1, 2, 3, 4, 5, 6]
even_numbers = list(filter(lambda x: x % 2 == 0, numbers))
print(even_numbers)

3. sorted()

students = [("Chandan", 25), ("Amit", 22), ("Ravi", 24)]
sorted_students = sorted(students, key=lambda x: x[1])
print(sorted_students)

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Advantages of Lambda Function

• Short and concise code
• Useful for temporary functions
• Improves readability in functional programming
• Commonly used with map(), filter(), and reduce()

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Limitations of Lambda

• Only one expression is allowed
• Cannot contain multiple statements
• Not suitable for complex logic

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Lambda vs Normal Function

• Lambda: Anonymous, single expression, used for short tasks
• Normal Function: Named, can contain multiple statements, suitable for complex logic

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Conclusion

Lambda expressions are powerful tools in Python that help write concise and functional-style code. They are best suited for short operations and are frequently used with higher-order functions like map(), filter(), and sorted(). Mastering Lambda functions will improve your efficiency in Python programming.