Python function basics

PYTHON4 functions: Global functions, local functions, lambda functions, methods

Many built-in functions

Syntax: def functionname (parameters):

Suite

Return is used to return the result object, which is optional: Returns multiple values separated by commas and grouped into tuples

Local variables, global variables, built-in variables

Global variable: Defining a Globals variable

Python's closures

Parameter passing form:

Position parameters: from left to right

Keyword parameters: matching by keyword name

Mix the above two ways: all positional parameters, all the keyword parameters

Use default parameters when defining functions: Parameters with default values

When mixing parameters with default and no default values, no default values are placed in front

Variable parameters: Parameters that start with * when defining a function, collect positional parameters, output tuple ()

When you define a function with a * * start, the phone keyword parameter, output dictionary {}

Variable parameter unpacking: When calling a function, use the * parameter, which can be used to scatter the parameter collection to pass any number of arguments based on the position or keyword

anonymous function lambda is an expression rather than a statement

Lambda Args:expression (args: A comma-separated variable)

Python function basics