以下Windows cmd代码段执行以下操作：

将pip升级到最新版本。升级所有过时的软件包。对于正在升级的每个包，检查requirements.txt中的任何版本说明符。

@echo off
Setlocal EnableDelayedExpansion
rem https://stackoverflow.com/questions/2720014/

echo Upgrading pip...
python -m pip install --upgrade pip
echo.

echo Upgrading packages...
set upgrade_count=0
pip list --outdated > pip-upgrade-outdated.txt
for /F "skip=2 tokens=1,3 delims= " %%i in (pip-upgrade-outdated.txt) do (
    echo ^>%%i
    set package=%%i
    set latest=%%j
    set requirements=!package!

    rem for each outdated package check for any version requirements:
    set dotest=1
    for /F %%r in (.\python\requirements.txt) do (
        if !dotest!==1 (
            call :substr "%%r" !package! _substr
            rem check if a given line refers to a package we are about to upgrade:
            if "%%r" NEQ !_substr! (
                rem check if the line contains more than just a package name:
                if "%%r" NEQ "!package!" (
                    rem set requirements to the contents of the line:
                    echo requirements: %%r, latest: !latest!
                    set requirements=%%r
                )
                rem stop testing after the first instance found,
                rem prevents from mistakenly matching "py" with "pylint", "numpy" etc.
                rem requirements.txt must be structured with shorter names going first
                set dotest=0
            )
        )
    )
    rem pip install !requirements!
    pip install --upgrade !requirements!
    set /a "upgrade_count+=1"
    echo.
)

if !upgrade_count!==0 (
    echo All packages are up to date.
) else (
    type pip-upgrade-outdated.txt
)

if "%1" neq "-silent" (
    echo.
    set /p temp="> Press Enter to exit..."
)
exit /b


:substr
rem string substition done in a separate subroutine -
rem allows expand both variables in the substring syntax.
rem replaces str_search with an empty string.
rem returns the result in the 3rd parameter, passed by reference from the caller.
set str_source=%1
set str_search=%2
set str_result=!str_source:%str_search%=!
set "%~3=!str_result!"
rem echo !str_source!, !str_search!, !str_result!
exit /b

这似乎对我有用。。。

pip install -U $(pip list --outdated | awk '{printf $1" "}')

之后，我使用带有空格的printf来正确分隔包名。

在我看来，这个选项更简单易懂：

pip install -U `pip list --outdated | awk 'NR>2 {print $1}'`

解释是，pip-list——过时输出所有过时包的列表，格式如下：

Package   Version Latest Type 
--------- ------- ------ -----
fonttools 3.31.0  3.32.0 wheel
urllib3   1.24    1.24.1 wheel
requests  2.20.0  2.20.1 wheel

在awk命令中，NR>2跳过前两条记录（行），｛print$1｝选择每行的第一个单词（正如SergioAraujo所建议的，我删除了tail-n+3，因为awk确实可以处理跳过记录）。

下面是用Python编写脚本的另一种方法：

import pip, tempfile, contextlib

with tempfile.TemporaryFile('w+') as temp:
    with contextlib.redirect_stdout(temp):
        pip.main(['list', '-o'])
    temp.seek(0)
    for line in temp:
        pk = line.split()[0]
        print('--> updating', pk, '<--')
        pip.main(['install', '-U', pk])

pip install --upgrade `pip list --format=freeze | cut -d '=' -f 1`

pip-list--format=freeze包括pip和setuptools。pip冻结不会。

一行（bash）。对我来说最短、最简单。

pip install -U $(pip freeze | cut -d = -f 1)

解释：

pip冻结返回每个包的package_name==版本cut-d=-f 1表示“对于每一行，返回第一行的字段，其中字段由=分隔”$（cmd）返回命令cmd的结果。因此，在这里，cmd将返回包名列表，pip install-U将对其进行升级。