'''
pip list --outdated #列出所有过期的库
单个python库更新
pip install --upgrade 库名
批量更新python库
第一种方式，不行采用第二种方式
imprt pip
from subprocess import call
for dist in pip.get_installed_distributions():
call("pip install --upgrade " + dist.project_name, shell=True)
'''
# 第二种方式
# from pip._internal.utils.misc import get_installed_distributions
# from subprocess import call
#
# for dist in get_installed_distributions():
# call("pip install --upgrade " + dist.project_name, shell=True)
