另一个可能的解决方案……

def gather_requirements(top_path=None):
    """Captures requirements from repo.

    Expected file format is: requirements[-_]<optional-extras>.txt

    For example:

        pip install -e .[foo]

    Would require:

        requirements-foo.txt

        or

        requirements_foo.txt

    """
    from pip.download import PipSession
    from pip.req import parse_requirements
    import re

    session = PipSession()
    top_path = top_path or os.path.realpath(os.getcwd())
    extras = {}
    for filepath in tree(top_path):
        filename = os.path.basename(filepath)
        basename, ext = os.path.splitext(filename)
        if ext == '.txt' and basename.startswith('requirements'):
            if filename == 'requirements.txt':
                extra_name = 'requirements'
            else:
                _, extra_name = re.split(r'[-_]', basename, 1)
            if extra_name:
                reqs = [str(ir.req) for ir in parse_requirements(filepath, session=session)]
                extras.setdefault(extra_name, []).extend(reqs)
    all_reqs = set()
    for key, values in extras.items():
        all_reqs.update(values)
    extras['all'] = list(all_reqs)
    return extras

然后使用…

reqs = gather_requirements()
install_reqs = reqs.pop('requirements', [])
test_reqs = reqs.pop('test', [])
...
setup(
    ...
    'install_requires': install_reqs,
    'test_requires': test_reqs,
    'extras_require': reqs,
    ...
)

我不建议做这样的事。正如多次提到的，install_requires和requirements.txt绝对不应该是同一个列表。但是由于涉及到pip的私有内部api，有很多误导性的答案，因此可能值得考虑更理智的替代方案……

没有pip，可以从setuptools setup.py脚本中解析一个相对简单的requirements.txt文件。setuptools项目已经在其顶级包pkg_resources中包含了必要的工具。

它或多或少是这样的:

#!/usr/bin/env python3

import pathlib

import pkg_resources
import setuptools

with pathlib.Path('requirements.txt').open() as requirements_txt:
    install_requires = [
        str(requirement)
        for requirement
        in pkg_resources.parse_requirements(requirements_txt)
    ]

setuptools.setup(
    install_requires=install_requires,
)

同样，这只适用于简单的requirements.txt文件。请参阅pkg_resources文档页中的需求解析，以获得关于所处理内容的详细信息。简而言之，每一行都应该是有效的PEP 508需求。不支持真正特定于pip的符号，这将导致失败。

警告之词

如前所述，不建议这样做。requirements.txt文件和“安装依赖项”列表是两个不同的概念，它们是不可互换的。

但是如果你确实写了一个setup.py安装脚本来读取requirements.txt，那么确保requirements.txt文件包含在“源发行版”(sdist)中，否则安装显然会失败。

自从setuptools版本62.6以来，可以在setup.cfg中写这样的东西:

[options]
install_requires = file: requirements.txt

或者在pyproject.toml中:

[project]
dynamic = ["dependencies"]

[tool.setuptools.dynamic]
dependencies = requirements.txt

上述忠告同样适用:

只支持非常简单的文件 该文件必须添加到sdist

此外，它目前被认为是一个“测试版”功能。

注:

另一个答案是:https://stackoverflow.com/a/59971236/11138259 https://caremad.io/posts/2013/07/setup-vs-requirement/ https://setuptools.pypa.io/en/latest/history.html#v62-6-0

从表面上看，requirements.txt和setup.py似乎是愚蠢的副本，但重要的是要理解，虽然形式相似，但预期的功能非常不同。

当指定依赖项时，包作者的目标是说“无论你在哪里安装这个包，为了使这个包工作，这些都是你需要的其他包。”

相反，部署作者(在不同的时间可能是同一个人)有不同的工作，因为他们说“这是我们收集和测试的包的列表，我现在需要安装”。

包作者为各种各样的场景编写程序，因为他们将自己的工作以他们可能不知道的方式使用，并且无法知道将在他们的包旁边安装哪些包。为了成为一个好邻居并避免与其他包的依赖版本冲突，它们需要指定尽可能广泛的依赖版本。这就是setup.py中的install_required所做的。

The deployment author writes for a very different, very specific goal: a single instance of an installed application or service, installed on a particular computer. In order to precisely control a deployment, and be sure that the right packages are tested and deployed, the deployment author must specify the exact version and source-location of every package to be installed, including dependencies and dependency's dependencies. With this spec, a deployment can be repeatably applied to several machines, or tested on a test machine, and the deployment author can be confident that the same packages are deployed every time. This is what a requirements.txt does.

So you can see that, while they both look like a big list of packages and versions, these two things have very different jobs. And it's definitely easy to mix this up and get it wrong! But the right way to think about this is that requirements.txt is an "answer" to the "question" posed by the requirements in all the various setup.py package files. Rather than write it by hand, it's often generated by telling pip to look at all the setup.py files in a set of desired packages, find a set of packages that it thinks fits all the requirements, and then, after they're installed, "freeze" that list of packages into a text file (this is where the pip freeze name comes from).

所以结论是:

setup.py should declare the loosest possible dependency versions that are still workable. Its job is to say what a particular package can work with. requirements.txt is a deployment manifest that defines an entire installation job, and shouldn't be thought of as tied to any one package. Its job is to declare an exhaustive list of all the necessary packages to make a deployment work. Because these two things have such different content and reasons for existing, it's not feasible to simply copy one into the other.

引用:

来自Python打包用户指南的install_requires vs Requirements文件。

它不能接受文件句柄。install_requires参数只能是字符串或字符串列表。

当然，您可以在设置脚本中读取您的文件，并将其作为字符串列表传递给install_requires。

import os
from setuptools import setup

with open('requirements.txt') as f:
    required = f.read().splitlines()

setup(...
install_requires=required,
...)

使用parse_requirements是有问题的，因为pip API没有公开的文档和支持。在pip 1.6中，该函数实际上是移动的，因此对它的现有使用可能会中断。

消除setup.py和requirements.txt之间重复的一个更可靠的方法是在setup.py中指定你的依赖项，然后输入-e。到requirements.txt文件中。关于为什么这是一种更好的方式，来自pip开发人员的一些信息可以在这里找到:https://caremad.io/blog/setup-vs-requirement/

你可以把它翻转过来，在setup.py中列出依赖项，并只有一个字符——一个点。-在requirements.txt中。

或者，即使不建议，仍然可以使用以下hack(用pip 9.0.1测试)解析requirements.txt文件(如果它没有通过URL引用任何外部需求):

install_reqs = parse_requirements('requirements.txt', session='hack')

但是这并不能过滤环境标记。

在pip的旧版本中，特别是6.0以上的版本中，可以使用一个公共API来实现这一点。需求文件可以包含注释(#)，也可以包含一些其他文件(——requirement或-r)。因此，如果你真的想解析一个requirements.txt文件，你可以使用pip解析器:

from pip.req import parse_requirements

# parse_requirements() returns generator of pip.req.InstallRequirement objects
install_reqs = parse_requirements(<requirements_path>)

# reqs is a list of requirement
# e.g. ['django==1.5.1', 'mezzanine==1.4.6']
reqs = [str(ir.req) for ir in install_reqs]

setup(
    ...
    install_requires=reqs
)