Lambda Function in Python Programming

Lambda function:

• A lambda function is an anonymous function (a function without a name).
• Define using the ‘lambda‘ keyword.
• Lambda functions can have any number of arguments.
• A lambda function is limited to a single expression.
• It is often used for a short period of time &  simple operations.

Syntax:

lambda arguments: expression

• arguments: Input parameters.
• expression: The operation to be performed, which will be returned as the output.

Uses of Lambda Functions:

1. Short Anonymous Functions: Lambda functions are useful when you need a small function for a short period of time and don’t want to define a full function using ‘def’.
2. Functional Programming: Commonly used with functions like ‘map()’, ‘filter()’, and ‘reduce()’ to apply a function to an iterable.
3. Sorting: Often used with sorting functions to provide custom sort keys.
4. Inline Operations: Ideal for operations that are small and won’t be reused elsewhere.

Examples:

# A lambda function to multiply by 100

Multiplyby100 = lambda x: x * 100

Multiplyby100(35)

Output:
3500

# Using Mapping function with above lambda function

my_list = [20,30,40,50,100]

list(map(Multiplyby100,my_list)) 

Output:
[2000, 3000, 4000, 5000, 10000]

#Using filter function with lambda

my_list = [5,6,7,8,9,10,11,12,13,14,15]

even = lambda x : x%2==0

list(filter(even,my_list))

Output:
[6, 8, 10, 12, 14]