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Improve invalid input type handling in tomllib.loads #124835
Description
Feature or enhancement
Proposal:
tomllib.loads only accepts str as input. Given bytes, it throws
TypeError: a bytes-like object is required, not 'str'
This is a bubbled up exception from the replace method on line
cpython/Lib/tomllib/_parser.py
Line 74 in 4129a74
While at it, I also propose catching any AttributeErrors from this line of code and raising the same new TypeError instead. As a result, a sensible TypeError is raised in nearly all cases where incorrect type is passed in.
Has this already been discussed elsewhere?
This is a minor feature, which does not need previous discussion elsewhere
Links to previous discussion of this feature:
Original issue report by @mechsin on Tomli's issue tracker: hukkin/tomli#223
PR: #124587
Activity
gh-124835: `tomllib.loads`: Raise TypeError not AttributeError. Impro…
StanFromIreland commentedon Apr 17, 2025
Do we want to backport this change? It is partly a bug fix (error message is flipped). Maybe it could be split?
See also: #132655
hauntsaninja commentedon Apr 17, 2025
I didn't backport because it can change the exception type (also because slightly less confusing error messages that aren't super critical are little more feature than bug, changes to error messages do sometimes break folks)