Why does Poetry skip awsapilib's dependency on 2captcha-python?

[iainelder]

Poetry skips the 2captcha dependency when resolving awsapilib's dependencies. Poetry says:

Invalid requirement (2captcha-python>=1.2.0) found in awsapilib-3.1.3 dependencies, skipping

The missing dependency causes the AccountManager class to fail with a ModuleNotFoundError.

awsapilib doesn't manage its dependencies using Poetry, so the library itself doesn't seem to be affected. It affects me when I add awsapilib to my own Poetry project.

I can work around the problem by adding 2captcha-python to my own project, but I'd rather understand and fix the problem in awsapilib itself if possible. See the original issue in the awsapilib project.

Here's a full repro in an empty directory.

$ poetry --version
Poetry (version 1.4.0)

$ poetry new .
Created package tmp.2023_05_18.kwpr1amm in .

$ poetry add awsapilib
Creating virtualenv tmp-2023-05-18-kwpr1amm-Kw2CPZUK-py3.8 in /home/isme/.cache/pypoetry/virtualenvs
Using version ^3.1.3 for awsapilib

Updating dependencies
Resolving dependencies... (0.0s)Invalid requirement (2captcha-python>=1.2.0) found in awsapilib-3.1.3 dependencies, skipping
Resolving dependencies... (4.4s)

Writing lock file

Package operations: 19 installs, 0 updates, 0 removals

  • Installing six (1.16.0)
  • Installing jmespath (1.0.1)
  • Installing python-dateutil (2.8.2)
  • Installing urllib3 (1.26.15)
  • Installing botocore (1.29.135)
  • Installing certifi (2023.5.7)
  • Installing charset-normalizer (3.1.0)
  • Installing idna (3.4)
  • Installing s3transfer (0.6.1)
  • Installing soupsieve (2.4.1)
  • Installing typing-extensions (4.5.0)
  • Installing beautifulsoup4 (4.12.2)
  • Installing boto3 (1.26.135)
  • Installing boto3-type-annotations (0.3.1)
  • Installing cachetools (5.3.0)
  • Installing opnieuw (2.0.0)
  • Installing pyotp (2.8.0)
  • Installing requests (2.30.0)
  • Installing awsapilib (3.1.3)

$ poetry run python -c 'from awsapilib import AccountManager; print("OK")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/isme/.cache/pypoetry/virtualenvs/tmp-2023-05-18-kwpr1amm-Kw2CPZUK-py3.8/lib/python3.8/site-packages/awsapilib/__init__.py", line 40, in <module>
    from .console import AccountManager, PasswordManager
  File "/home/isme/.cache/pypoetry/virtualenvs/tmp-2023-05-18-kwpr1amm-Kw2CPZUK-py3.8/lib/python3.8/site-packages/awsapilib/console/__init__.py", line 35, in <module>
    from .console import AccountManager, PasswordManager
  File "/home/isme/.cache/pypoetry/virtualenvs/tmp-2023-05-18-kwpr1amm-Kw2CPZUK-py3.8/lib/python3.8/site-packages/awsapilib/console/console.py", line 45, in <module>
    from awsapilib.captcha import Solver, Iterm, Terminal
  File "/home/isme/.cache/pypoetry/virtualenvs/tmp-2023-05-18-kwpr1amm-Kw2CPZUK-py3.8/lib/python3.8/site-packages/awsapilib/captcha/__init__.py", line 34, in <module>
    from .captcha import Solver, Iterm, Terminal, Captcha2
  File "/home/isme/.cache/pypoetry/virtualenvs/tmp-2023-05-18-kwpr1amm-Kw2CPZUK-py3.8/lib/python3.8/site-packages/awsapilib/captcha/captcha.py", line 40, in <module>
    from twocaptcha import TwoCaptcha, ValidationException, TimeoutException
ModuleNotFoundError: No module named 'twocaptcha'

$ poetry add 2captcha-python
Using version ^1.2.0 for 2captcha-python

Updating dependencies
Resolving dependencies... (0.0s)Invalid requirement (2captcha-python>=1.2.0) found in awsapilib-3.1.3 dependencies, skipping
Resolving dependencies... (0.1s)

Writing lock file

Package operations: 1 install, 0 updates, 0 removals

  • Installing 2captcha-python (1.2.0)

$ poetry run python -c 'from awsapilib import AccountManager; print("OK")'
OK

[radoering]

>>> Dependency.create_from_pep_508("2captcha-python>=1.2.0")
lark.exceptions.UnexpectedCharacters: No terminal matches '2' in the current parser context, at line 1 col 1
2captcha-python>=1.2.0
^
Expected one of: 
	* NAME

Poetry just does not support packages starting with a digit:
https://github.com/python-poetry/poetry-core/blob/1ba6836a2d9ca4fa1042bc506129e452b7c86955/src/poetry/core/version/grammars/pep508.lark#L13

According to PEP 508:

identifier    = letterOrDigit identifier_end*
name          = identifier

Looks like a Poetry bug.

[iainelder]

Thanks, @radoering . That may explain why Poetry fails to process the transitive dependency. (myapp -> awsapilib -> 2captcha-python)

But why does the same not happen when I depend on the package directly? (myapp -> 2captcha-python)

[radoering]

Because Poetry does not adhere to PEP 508 (yet) for specifying dependencies. Thus, Dependency.create_from_pep_508() is never called.

[iainelder]

Thanks, @radoering . I submitted a PR to allow a leading digit in a dependency.

It's my first time contributing to Poetry Core. Can you give me feedback on it?