Python Lambda Brief Introduction

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Python Lambda

In Python, if you want to create a function using the keyword DEF, and if you want to create an anonymous function, you need to use lambda.

What is the difference between a function created by lambda and a function created by def?

1. Def creates a function that has a name, and Lambda has no
2. Lambda creates an object of a function, but does not give the object an identifier, and Def assigns the function object to a variable

3. DEF is a statement, and Lambda is just an expression

   y = lambda x:print (x)
   Y (10) # 10

For example, an expression is created with lambda, and X is equivalent to a formal parameter, and the code as a whole is very simple and efficient.

Typically, a lambda can be directly a member of a list or dictionary, as follows:

So the same operation, in the list, can only use lambda, there is no way to use def substitution, because DEF is a statement, in the list can only be an expression. A lambda expression can have only one expression after ":", usually the return statement can be returned to be placed behind a lambda, and cannot be returned after the same cannot be placed. Therefore, it is best not to put a statement such as if or for in the back of a lambda expression, and lambda is best used only to define simple functions.

Python Lambda Brief Introduction