2.3.1.post1.dev1 is not newer then 2.3.1

[Paebbels]

Environment

• pip version: 19.3.1 (pip3)
• Python version: CPython, 3.8.1
• OS: Windows 10, x64-86

Description
I'm patching packages from Sphinx core, because the developers don't want to add these updates. I created a Git repository on GitHub and my own package namespace for the patched variations. For tagging I use the original version number with postfix 2.3.1.postN to create post-releases. Development versions of such post-releases are tagged additionally with .devN like 2.3.1.post1.dev1.

(Other version postfixes for releases after 2.3.1 are not accepted by PyPI due to rules in PEP440.)

To summarize:

• 2.3.1 - commit with original code based on Sphinx 2.3.1
• 2.3.1.post1.dev1 - code based on 2.3.1 for development towards 2.3.1.post1
• 2.3.1.post1 - code based on 2.3.1 with my patches

I packages and pushed this to PyPI.
Next, I changed my requirements.txt file and added:

btd.sphinx.graphviz>=2.3.1

According to PEP440, section post-releases, a post-release is newer than a release.

But pip reports differently:

(See below for a non-screenshot version.)

I looks like version postfixes like .postN and .devN are not handled correctly in relational operators.

Expected behavior

pip should accept post-releases as newer version than an ordinary release.

How to Reproduce

1. Get package from PyPI:

   pip install -U btd.sphinx.inheritance-diagram

2. An error occurs.

Output

C:\WINDOWS\system32> py -3 -m pip install -U btd.sphinx.inheritance-diagram
Collecting btd.sphinx.inheritance-diagram
  Using cached https://files.pythonhosted.org/packages/77/e2/c287faaf9a5d7cb617b6b2515f16862c1b15a381d85860bab0a6f015cd21/btd.sphinx.inheritance_diagram-2.3.1.post1-py3-none-any.whl
ERROR: Could not find a version that satisfies the requirement btd.sphinx.graphviz>=2.3.1 (from btd.sphinx.inheritance-diagram) (from versions: 2.3.1.post1.dev1)
ERROR: No matching distribution found for btd.sphinx.graphviz>=2.3.1 (from btd.sphinx.inheritance-diagram)

[Paebbels]

I managed to create a post-release without .dev1 postfix. This works and my package and its dependencies were installed. So I would reduce my error report to:

.postN in combination with .devN does not work as expected.

After publishing 2.3.1.post1 on PyPI (2.3.1.post1.dev1 is still in the PyPI archive), I get these outputs:

C:\WINDOWS\system32> py -3 -m pip install btd.sphinx.inheritance-diagram
Collecting btd.sphinx.inheritance-diagram
  Using cached https://files.pythonhosted.org/packages/77/e2/c287faaf9a5d7cb617b6b2515f16862c1b15a381d85860bab0a6f015cd21/btd.sphinx.inheritance_diagram-2.3.1.post1-py3-none-any.whl
Requirement already satisfied: sphinx>=2.3.1 in c:\program files\python3.8\lib\site-packages (from btd.sphinx.inheritance-diagram) (2.3.1)
Collecting btd.sphinx.graphviz>=2.3.1
  Using cached https://files.pythonhosted.org/packages/3b/37/0dcebcf413260211501e350128f47b542fe5a79072edb40b742e5318d3c7/btd.sphinx.graphviz-2.3.1.post1-py3-none-any.whl
Requirement already satisfied: babel!=2.0,>=1.3 in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2.8.0)
Requirement already satisfied: sphinxcontrib-htmlhelp in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.0.2)
Requirement already satisfied: Jinja2>=2.3 in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2.10.3)
Requirement already satisfied: sphinxcontrib-jsmath in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.0.1)
Requirement already satisfied: packaging in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (20.0)
Requirement already satisfied: Pygments>=2.0 in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2.5.2)
Requirement already satisfied: sphinxcontrib-devhelp in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.0.1)
Requirement already satisfied: requests>=2.5.0 in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2.22.0)
Requirement already satisfied: alabaster<0.8,>=0.7 in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (0.7.12)
Requirement already satisfied: sphinxcontrib-applehelp in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.0.1)
Requirement already satisfied: setuptools in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (45.0.0)
Requirement already satisfied: sphinxcontrib-qthelp in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.0.2)
Requirement already satisfied: docutils>=0.12 in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (0.16)
Requirement already satisfied: colorama>=0.3.5; sys_platform == "win32" in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (0.4.3)
Requirement already satisfied: snowballstemmer>=1.1 in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2.0.0)
Requirement already satisfied: imagesize in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.2.0)
Requirement already satisfied: sphinxcontrib-serializinghtml in c:\program files\python3.8\lib\site-packages (from sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.1.3)
Requirement already satisfied: pytz>=2015.7 in c:\program files\python3.8\lib\site-packages (from babel!=2.0,>=1.3->sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2019.3)
Requirement already satisfied: MarkupSafe>=0.23 in c:\program files\python3.8\lib\site-packages (from Jinja2>=2.3->sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.1.1)
Requirement already satisfied: six in c:\program files\python3.8\lib\site-packages (from packaging->sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.13.0)
Requirement already satisfied: pyparsing>=2.0.2 in c:\program files\python3.8\lib\site-packages (from packaging->sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2.4.6)
Requirement already satisfied: urllib3!=1.25.0,!=1.25.1,<1.26,>=1.21.1 in c:\program files\python3.8\lib\site-packages (from requests>=2.5.0->sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (1.25.7)
Requirement already satisfied: certifi>=2017.4.17 in c:\program files\python3.8\lib\site-packages (from requests>=2.5.0->sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2019.11.28)
Requirement already satisfied: chardet<3.1.0,>=3.0.2 in c:\program files\python3.8\lib\site-packages (from requests>=2.5.0->sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (3.0.4)
Requirement already satisfied: idna<2.9,>=2.5 in c:\program files\python3.8\lib\site-packages (from requests>=2.5.0->sphinx>=2.3.1->btd.sphinx.inheritance-diagram) (2.8)
Installing collected packages: btd.sphinx.graphviz, btd.sphinx.inheritance-diagram
Successfully installed btd.sphinx.graphviz-2.3.1.post1 btd.sphinx.inheritance-diagram-2.3.1.post1

[chrahunt]

Any .devN suffix causes the version to be considered a "prerelease" here. It should work as desired if you pass --pre to pip install.

[Paebbels]

Does it also work with requirements.txt files?
What is the syntax?

[chrahunt]

It would look like

pip install --pre btd.sphinx.inheritance-diagram

or

pip install -r requirements.txt

with a requirements.txt like

--pre
btd.sphinx.inheritance-diagram

[uranusjr]

To clarify, pip does correctly treat 2.3.1.post1.dev1 as newer than 2.3.1 (so the issue title is inaccurate). The problem here is that pip is not selecting the (newer) dev1 version with --pre. This is also discussed in #7579 and discuss.python.org (slightly different cases, but worth reading if you’re interested in how pip works in this area).

[no-response]

This issue has been automatically closed because there has been no response to our request for more information from the original author. With only the information that is currently in the issue, we don't have enough information to take action. Please reach out if you have or find the answers we need so that we can investigate further.