【function】
1 A python program consists of packages, modules and functions. A package is a collection of modules. A module is a collection of functions and classes that deal with a certain class of problems.
A 2 pack is a toolbox for a specific task.
3 The package must contain an __init__.py file that identifies the current folder as a package.
4 Python programs are composed of modules. A module organizes a group of related functions or code into a file, and a file is a module. Modules consist of code, functions, and classes. Importing a module uses the import statement.
5 The role of the package is to achieve program reuse.