Question

我创建了一个脚本（请参阅下文）以升级我的所有pip包。我通过idle3成功执行了脚本，即使用idle3打开脚本并按F5将脚本作为模块运行。但是，我无法在终端中执行它；出现以下错误。 如何克服此错误？为什么导入错误发生在终端中，而不发生在idle3中？

$ python3 -m upgrade_pip_packages 
====================================================
UPGRADING ALL --USER PIP PACKAGES TO LATEST VERSION:
====================================================
Traceback (most recent call last):
  File "/usr/bin/pip", line 9, in <module>
    from pip import main
ImportError: cannot import name main
ERROR: Command 'pip list' returned non-zero exit status 1

我的脚本： upgrade_pip_packages.py

#!/bin/python3
import subprocess
from pprint import pprint


def get_pkgs():
    try:
        cmd = 'pip list'
        completed = subprocess.run( cmd, shell=True, check=True,
                                    stdout=subprocess.PIPE )
    except subprocess.CalledProcessError as err:
        print( 'ERROR:', err )
    else:
        for line in completed.stdout.decode('utf-8').splitlines()[2:]:
            yield line


def update_pkgs(piplist):
    npackages = 0
    nupgrades = 0
    nerrors = 0
    upgradelist = []
    errorlist = []
    for i in piplist:
        npackages += 1
        pkgname, ver = i.split()
        print('\n',pkgname)
        try:
            cmd = 'pip install --user {} --upgrade'.format(pkgname)
            completed = subprocess.run( cmd, shell=True, check=True,
                                        stdout=subprocess.PIPE )
        except subprocess.CalledProcessError as err:
            nerrors += 1
            errorlist.append(pkgname)
            print( 'ERROR: {}'.format(err) )
        else:
            for line in completed.stdout.decode('utf-8').splitlines():
                print(line)
                if 'Successfully installed' in line:
                    nupgrades +=1
                    upgradelist.append(pkgname)
    return npackages, nupgrades, nerrors, upgradelist, errorlist


def main():
    print('====================================================')
    print('UPGRADING ALL --USER PIP PACKAGES TO LATEST VERSION:')
    print('====================================================')
    pip_pkgs = get_pkgs() # created a generator
    npackages, nupgrades, nerrors, upgradelist, errorlist \
               = update_pkgs(pip_pkgs)
    print('\nNo. of --user pip packages = {}'.format(npackages))
    print('No. of upgrades            = {}'.format(nupgrades))
    print('No. of upgrade errors      = {}'.format(nerrors))
    if upgradelist:
        print('Package(s) upgraded:')
        pprint(upgradelist)
    if errorlist:
        print('Package(s) with upgrade error:')
        pprint(errorlist)
    print()


if __name__ == '__main__':
    main()

Answer 1

最终upgrade_pip_packages.py。

我找到了问题的answer。本质上，我的脚本必须：

import sys

并进行以下修改：

cmd = [sys.executable, '-m', 'pip', 'list'] #Change here
completed = subprocess.run( cmd,
                            #shell=True, #switch this off
                            check=True,
                            stdout=subprocess.PIPE )

和

cmd = [sys.executable, '-m', 'pip', 'install', '--user', pkgname, '--upgrade'] #Change here
completed = subprocess.run( cmd,
                            #shell=True, #switch this off
                            check=True,
                            stdout=subprocess.PIPE )

PyPA documentation解释：

建议在其中编写{sys.executable}而不是普通的python 为了确保命令在Python安装中运行匹配当前正在运行的笔记本（可能不一样） python命令所指的Python安装）。

$ pip --version
pip 18.1 from ~/.local/lib/python3.5/site-packages/pip (python 3.5)
$ pip3 --version
pip 18.1 from ~/.local/lib/python3.5/site-packages/pip (python 3.5)

终端中的python3子进程pip“ ImportError：无法导入名称main”

1 个答案: