Comprehensive analysis of Lambda expressions in Python

What is a Lambda expression

"Lambda expression" (lambda expression) is an anonymous function. Lambda expression is named based on the lambda calculus in mathematics. It directly corresponds to the lambda abstraction (lambda abstraction). It is an anonymous function, that is, a function without a function name. . Lambda expressions can represent closures (note that they are different from the traditional mathematical sense).

Lambda is an anonymous function. When we need to call a certain function repeatedly and don’t want to write so much code, we can use lambda expressions instead.

Universal format of lambda:

lambda argument: manipulate(argument)

Sample code:

add = lambda x,y : x + y
print add(3,5)
#output: 8

Usage:

Sort.

a = [(1, 2), (4, 1), (9, 10), (13, -3)]
a.sort(key=lambda x: x[1])
print(a)
# Output: [(13, -3), (4, 1), (1, 2), (9, 10)]