Fix the parsing of wildcards dependency constraints

[sdispater]

Resolves: python-poetry/poetry#4176

• Added tests for changed code.
• Updated documentation for changed code.

[bentheiii]

I think this fix is incorrect, as name < 3.* should accept version3.6.0, I think name < 3.* should be normalized to name < 4

[finswimmer]

Hello @bentheiii,

name < 3.* could be read as "any version smaller 3.anything". So it's < 3.

I think this fix is incorrect.

Please don't call it a "fix" (even it's in the title ;) ). It's a (temporary) workaround, to mimic pip's wrong behavior of allowing this kind of invalid PEP 440 constraint. Otherwise to many packages cannot be installed anymore. (See also: https://discuss.python.org/t/pep-440-wildcard-usage-in-comparison-clause/10045)

[bentheiii]

It is indeed a pretty unclear whether name (?) X.* should resolve to "version chosen must match the constraint for any X.*" or "version chosen must match the constraint for all X.*". But since name > 3.* resolves to name > 3, poetry obviously goes with the former. Therefore, name < 3.* has to be less than any version 3.* , it has to only be less than an arbitrarily high *, normalizing to name < 4 (just like how name > 3.* must be higher than an arbitrarily low *, normalizing to name > 3).

[furlongm]

Would it be possible to make a prerelease that contains this fix/workaround? We are trying to use newer features of poetry but this issue is holding us back.

[edgarrmondragon]

@furlongm is there a reason not to install from master in the meantime if the feature you need is there?

[furlongm]

@furlongm is there a reason not to install from master in the meantime if the feature you need is there?

Mostly a desire to pin the poetry dependencies at a specific version so it's not a moving target - also don't always have access to github but do have a pypi mirror, so released versions are a lot more accessible.