Python Lambda

Python Lambda

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

Syntax

lambda arguments : expression

Example

Add 10 to argument a, and return the result:

x = lambda a : a + 10
print(x(5))

Lambda functions can take any number of arguments:

# Multiply argument a with argument b and return the result:
x = lambda a, b : a * b
print(x(5, 6))

Why Use Lambda Functions?

The power of lambda is better shown when you use them as an anonymous function inside another function. Say you have a function definition that takes one argument, and that argument will be multiplied with an unknown number:

def myfunc(n):
  return lambda a : a * n

mydoubler = myfunc(2)
mytripler = myfunc(3)

print(mydoubler(11))
print(mytripler(11))

Use lambda functions when an anonymous function is required for a short period of time.