When there are many functional modules in an application or project, it is unreasonable to put them in the same folder; at this time, packages in Python can be used to manage more functional modules. Using packages can effectively avoid name conflicts and facilitate package maintenance and management.
1. Package call
A package is actually a folder or directory that must contain a file named "__init__.py", which can be an empty file, just to indicate that the directory is a package.
Call of the module in the package :
call the hdl() function in the index.py module in the handle package
- import handle.index #调用handle.index.hdl()
- from handle import index # 调用 index.hdl()
- from handle.index import hdl #调用hdl()
2, the initialization of the package
The first time any part of the package is imported, the code in the "__init__.py" file is executed, where variable and function names are also imported automatically. Can include initializing working code for the package and setting the "__all__" variable.
Example of package:
#包的名字bao
#文件名：__init__.py
name = 'MyName'
print('包中的name:', name)#包中的模块
#文件名：MyPyModel.py
class MyTestModel:
def __init__(self, value=10):
self.value = value
def getValue(self):
return self.value
def setValue(self, value):
self.value = value
if __name__ == '__main__':
myTest = MyTestModel('ModelTest')
print(myTest.getValue())#包的使用
import bao.MyPyModel
if __name__ == '__main__':
test = bao.MyPyModel.MyTestModel(20)
print(test.getValue())
print('outSide:', bao.name)Running result:
name in the package: MyName
20
outSide: MyName