PEP 787: Safer subprocess usage using t-strings

[blhsing (Ben Hsing)]

@pitrou

That’s certainly a matter of perception. Personally I’d rather read a list of arguments, because I know that there will be no splitting issues if some arguments have whitespace or other special characters in them.

Given that t-strings don’t seem like they would be able to eliminate all issues with splitting, I’m not sure I would like to read them in that context.

True. A t-string can’t unambiguously split t"echo 'Hello, World!'" across platforms even with shell=False unless we document the splitting to always follow the shlex/bash logics, which may be counter-intuitive to some Windows users unfortunately.

In many real-world use cases where spaces and special characters are not part of the literal arguments of a command line though, I think t-string can still be a more readable option, and we may just have to document the limitations like we already do for shell=True in the Security Considerations section.

Also, as I pointed above, it’s easy to misread a leading “f” as a “t” or the reverse.

This sounds like an argument against PEP750: Template Strings (new updates) rather than this proposal though.