Lambda Functions in Python (Anonymous Functions) 🚀

A lambda function is a small, anonymous function that can have any number of arguments but only one expression.

✅ Useful for short, throwaway functions
✅ More concise than regular def functions
✅ Often used with functions like map(), filter(), and sorted()

1️⃣ Syntax of a Lambda Function

📌 Syntax:


lambda arguments: expression

📌 Example:


square = lambda x: x * x
print(square(5)) # Output: 25

🔹 The function takes x as an argument and returns x * x.

2️⃣ Lambda vs. Regular Function

📌 Regular function using def:


def add(a, b):
return a + b

print(add(3, 5)) # Output: 8

📌 Same function using lambda:


add = lambda a, b: a + b
print(add(3, 5)) # Output: 8

🚀 Lambda is more concise but limited to one expression.

3️⃣ Using Lambda with map(), filter(), and sorted()

🔹 map() – Apply a Function to Each Element

numbers = [1, 2, 3, 4]
squared = list(map(lambda x: x ** 2, numbers))
print(squared) # Output: [1, 4, 9, 16]
🔹 filter() – Keep Elements That Meet a Condition

numbers = [10, 15, 20, 25, 30]
even_numbers = list(filter(lambda x: x % 2 == 0, numbers))
print(even_numbers) # Output: [10, 20, 30]

🔹 sorted() – Custom Sorting

students = [("Alice", 25), ("Bob", 20), ("Charlie", 23)]
students_sorted = sorted(students, key=lambda x: x[1]) # Sort by age
print(students_sorted)
# Output: [('Bob', 20), ('Charlie', 23), ('Alice', 25)]

4️⃣ Lambda with if-else (Ternary Condition)

max_value = lambda a, b: a if a > b else b
print(max_value(10, 20)) # Output: 20

5️⃣ When to Use Lambda Functions?

✅ When you need a short, one-time-use function

✅ When passing a function as an argument (e.g., map(), filter())

✅ When writing concise code

🚨 Avoid using lambda for complex logic—use def instead for readability!

    Date: 2025-03-22 00:00:00.000000