python怎么import自己写的包

mypac.py:

def myfunc():
    return 'this is a function of mypac'

if __name__=='__main__':
    print('executing '+__name__)
    print(myfunc())
else:
    print('executing '+__name__)

main.py:

import mypac

print('--------')
print(mypac.myfunc())

执行mypac.py:

executing __main__
this is a function of mypac

执行main.py:

executing mypac
--------
this is a function of mypac

执行完main.py后生成这个：