anonymous function-lambda in Python

Briefly

In addition to the DEF statement, Python provides a form of expression that generates a Function object. This expression creates a function that can then be called, but it returns a function instead of assigning the function to a variable name.

Lambda expression

The general form of a lambda is the keyword lambda, followed by one or more parameters, followed by a colon, followed by an expression: Lambda argument1 argument2 ...: expression using arguments

A lambda is an expression, not a statement.

As an expression, lambda returns a value that can optionally be assigned to a variable name. Instead, the DEF statement always assigns a new function to a variable name at the head, rather than returning the function as a result.

A lambda body is a single expression, not a block of code.

The default parameters can also be used in lambda parameters, just as they are used in def.

>>>x = (Lambda a = "www.", b = "Pythontab", c = ". com": A + b +c)

>>>x ("BBS")

' Bbs.pythontab.com '

Why use Lambda

1. When using Python to write some execution scripts, using lambda eliminates the process of defining a function and makes the code more streamlined.

2. For some abstract functions that are not reused elsewhere, sometimes it is difficult to name a function, and using lambda does not have to consider naming problems.

3. Using lambda makes the code easier to understand at some point.

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