feat: add to_lowercase and to_uppercase to PandasExpr.str namespace
#455
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FBruzzesi
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to_lowercase and to_uppercase to Expr.str namespace to_lowercase and to_uppercase to PandasExpr.str namespace
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Will fix the doctests ! π« |
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Amazing! Well done @lucianosrp for figuring it all out!
I just have some really minor comments
I think we can probably also support this for pyarrow.Table, right? Fancy changing constructor to constructor_with_pyarrow in the test, and implementing this in narwhals/_arrow/series.py and narwhals/_arrow/expr.py? It should be quite similar to what you've already done
Again, seriously good work here, great to have you on board π
Co-authored-by: Marco Edward Gorelli <[email protected]>
Co-authored-by: Marco Edward Gorelli <[email protected]>
Ah, right! I probably have missed this..I will add that too |
| Notes: | ||
| The PyArrow backend will convert 'Γ' to 'αΊ' instead of 'SS'. | ||
| For more info see [the related issue](https://github.com/apache/arrow/issues/34599). | ||
| There may be other unicode-edge-case-related variations across implementations. |
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Not sure how much we want to expand on this topic, but I would consider adding some additional information, such as mentioning that pyarrow is based on utf8proc for sake of completeness.
WDYT?
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sure, happy to take this as a follow-up! π for now I'll merge as-is
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amazing, thanks @lucianosrp !
we're really keen to expand pyarrow functionality so any PRs in that direction are extremely welcome!
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My pleasure, @MarcoGorelli This is an awesome tool! π₯ I am happy to help expanding it! |
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This feature allows to convert strings to upper and lower case variants, similar to what is already possible with polars'
Expr.str.to_lowercase()and pandas'Series.str.lower()Unicode caveat
There is a caveat for PyArrow's backend that converts the character 'Γ' to uppercase 'αΊ' instead of 'SS'. There are probably few others Unicode edgecases but I think the vast majority of users won't be affected. This has been documented in the
to_uppercasemethod and linked the issue: apache/arrow#34599This was my first contribution here, feedback is always welcomed π