python import报错

1. 导入路径
   import sys
   sys.path
   ['',
   '../',
   '/Users/delron/.virtualenv/py3/bin',
   '/Users/delron/.virtualenv/py3/lib/python36.zip',
   '/Users/delron/.virtualenv/py3/lib/python3.6',
   '/Users/delron/.virtualenv/py3/lib/python3.6/lib-dynload',
   '/usr/local/Cellar/python3/3.6.0_1/Frameworks/Python.framework/Versions/3.6/lib/python3.6',
   '/Users/delron/.virtualenv/py3/lib/python3.6/site-packages',
   '/Users/delron/.virtualenv/py3/lib/python3.6/site-packages/IPython/extensions',
   '/Users/delron/.ipython',
   ]

sys.path.append("../")
sys.path.insert(1, "../")

2.导入时 python解释器会维护一个包的副本 （缓存） 在内存中

让新模块生效的方式：
1. 重新启动
2. imp.reload()

3.导入同级或上级目录的文件可在模块前加上相对路径