Python Lambda Function

A lambda function in Python is a small, anonymous function defined with the lambda keyword. It can take any number of arguments but can have only one expression. Lambda functions are useful when a short, throwaway function is needed.

Python में lambda function एक छोटा, गुमनाम function होता है जिसे lambda keyword से बनाया जाता है। यह कई arguments ले सकता है लेकिन केवल एक expression हो सकता है। जब short और temporary function चाहिए, तब इसका उपयोग किया जाता है।

Why Use Lambda Functions?

• To write short functions without naming them
• Useful inside functions like map(), filter(), reduce()
• Improves code readability in concise operations

• Short और बिना नाम के functions लिखने के लिए
• map(), filter(), reduce() जैसी functions में उपयोगी
• Code को छोटा और readable बनाता है

Lambda Function Examples

1. Add 2 numbers

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

   Output:

   8

2. Square of a number

   Copysquare = lambda x: x * x
   print(square(6))

   Output:

   36

3. Check even number

   Copyis_even = lambda x: x % 2 == 0
   print(is_even(4))

   Output:

   True

4. Sort list by second element of tuple

   Copypairs = [(1, 5), (2, 3), (4, 1)]
   pairs.sort(key=lambda x: x[1])
   print(pairs)

   Output:

   [(4, 1), (2, 3), (1, 5)]

5. Use with map()

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

   Output:

   [1, 4, 9]

6. Use with filter()

   Copynums = [1, 2, 3, 4]
   evens = list(filter(lambda x: x%2==0, nums))
   print(evens)

   Output:

   [2, 4]

7. Use with reduce()

   Copyfrom functools import reduce
   nums = [1, 2, 3, 4]
   product = reduce(lambda x, y: x * y, nums)
   print(product)

   Output:

   24

8. Maximum of two numbers

   Copymaximum = lambda a, b: a if a > b else b
   print(maximum(10, 15))

   Output:

   15

9. Convert Celsius to Fahrenheit

   Copyc_to_f = lambda c: (c * 9/5) + 32
   print(c_to_f(0))

   Output:

   32.0

10. Return length of string

    Copylength = lambda s: len(s)
    print(length("Python"))

    Output:

    6