python package 的两种组织方式

方式一
/package1/

.../__init__.py

        # 空文件

.../class1.py

        class Class1:
            def __init__(self):
                self.name = "class one"

            def printInfo(self):
                print("i am class One!")

.../class2.py

        class Class2:
            def __init__(self):
                self.name = "class two"

            def printInfo(self):
                print("i am class two!")

/demo1.py

    from package1.class1 import Class1
    from package1.class2 import Class2

    if __name__ == "__main__":
        c1 = Class1()
        c1.printInfo()
        c2 = Class2()
        c2.printInfo()

#####################################

方式二

/package2/
.../__init__.py

        from .class1 import Class1
        from .class2 import Class2

... /class1.py

        class Class1:
            def __init__(self):
                self.name = "class one"

            def printInfo(self):
                print("i am class One!")

.../class2.py

        class Class2:
            def __init__(self):
                self.name = "class two"

            def printInfo(self):
                print("i am class two!")

/demo2.py

    from package2 import Class1, Class2

    if __name__ == "__main__":
        c1 = Class1()
        c1.printInfo()
        c2 = Class2()
        c2.printInfo()