Python3.8以下这样一键更新所有包：
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)
Python3.8以上这样一键更新所有包：
import pip
from subprocess import call
from importlib import metadata as importlib_metadata
# 上一条语句在低版本中可能要改成 import importlib_metadata
for dist in importlib_metadata.distributions():
print("Updating for:", dist.metadata["Name"]) # 看进度用，非必需
call("pip install -U " + dist.metadata["Name"], shell=True)
