Add Message.python_brace_format
#1169
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Codecov ReportAll modified and coverable lines are covered by tests ✅
Additional details and impacted files@@ Coverage Diff @@
## master #1169 +/- ##
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+ Coverage 91.31% 91.37% +0.05%
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Files 27 27
Lines 4654 4672 +18
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+ Hits 4250 4269 +19
+ Misses 404 403 -1
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babel/messages/catalog.py
Outdated
| def _has_python_brace_format(string: str) -> bool: | ||
| fmt = Formatter() | ||
| try: | ||
| parsed = list(fmt.parse(string)) | ||
| except ValueError: | ||
| return False | ||
| return any(True for _, field_name, *_ in parsed if field_name is not None) |
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How about
| def _has_python_brace_format(string: str) -> bool: | |
| fmt = Formatter() | |
| try: | |
| parsed = list(fmt.parse(string)) | |
| except ValueError: | |
| return False | |
| return any(True for _, field_name, *_ in parsed if field_name is not None) | |
| def _has_python_brace_format(string: str) -> bool: | |
| if "{" not in string: | |
| return False | |
| fmt = Formatter() | |
| try: | |
| # `fmt.parse` returns 3-or-4-tuples of the form | |
| # `(literal_text, field_name, format_spec, conversion)`; | |
| # if `field_name` is set, this smells like brace format | |
| return any(t[1] is not None for t in fmt.parse(string)) | |
| except ValueError: | |
| return False |
?
- fast path first
- no reason to gather the result to a list first that I can think of
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Agreed on both, there is no need to convert the result to a list, it just didn't occur to me when I wrote it 😅
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Actually, there is a subtle difference. Consider the string {} {. If you try to format it, you'll get a ValueError because of the unclosed second brace which makes it invalid. However, _has_python_brace_format will return True because the any short-circuits before the parser gets to the invalid brace.
This might be a bit surprising. Perhaps we should only return True if the whole string is valid?
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Mm, fair! Maybe the any could be rewritten as a not all(...) (with a suitable comment above it to explain why the strange construction!) so we do always parse the entire thing?
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I went for a loop in the end because I find it to be a bit easier to read compared to not all(...) but I'm happy to change it if you prefer!
Co-authored-by: Aarni Koskela <akx@iki.fi>
Relevant issue: #333
Part 1 of adding support for checking f-string parameters. This simply adds a new property on the
Messageobject analogous topython_formatwhich sets the corresponding flag. In a followup PR I'm going to add a checker for the f-string format (reusing my implementation from #1168)@akx (I can't ask for a review so I'm tagging you ;))