How to specify a one item list with a comma in it?

[wshanks]

In tox.ini, if I put the following:

[tox]
requires =
     tox>=4.6.4,<5

I get a parsing error:

packaging.requirements.InvalidRequirement: Expected package name at the start of dependency specifier                                                                                                                                         
    <5 

It seems that it is treating the requires content as a comma delimited list. If instead I use:

[tox]
requires =
     tox>=4.6.4,<5
     tox>=4.6.4,<5

tox runs normally because now it is treating the entry as a newline delimited list and not interpreting the commas. Is there a way to make a one item list with a comma in it without having the comma interpreted?

[gaborbernat]

This is a known behavior of the INI format parser — single-line lists are split on commas. The workaround you found (duplicating the line to force newline-delimited parsing) works, but a cleaner approach is to quote nothing and just ensure newline separation:

[tox]
requires =
    tox>=4.6.4,<5

If this still splits on the comma even with newline format, this would be a bug in the list parser. However, with tox.toml this is not an issue since TOML has proper array syntax:

[tox]
requires = ["tox>=4.6.4,<5"]

[gaborbernat]

Converted to issue #3861