python中根据字符串导入模块modu

import importlib

modname = 'datetime'

datetime_module = importlib.import_module(modname)

print(datetime_module)
# <module 'datetime' from 'C:\\Users\\huchengyue\\AppData\\Local\\Programs\\Python\\Python37\\lib\\datetime.py'>

obj = getattr(datetime_module,'datetime')

print(obj.now())
# 2019-03-05 23:25:16.077121

print(dir(datetime_module))
# ['MAXYEAR', 'MINYEAR', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', 'date', 'datetime', 'datetime_CAPI', 'time', 'timedelta', 'timezone', 'tzinfo']