Fix StopIteration bug for Python 3.7+ (PEP 479 compliance) #27
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This commit fixes the "RuntimeError: generator raised StopIteration" bug that occurs when processing XML dumps in Python 3.7+. Problem: -------- PEP 479 (enforced in Python 3.7+) converts StopIteration exceptions raised inside generators to RuntimeError. The mwxml library violated this by calling next() inside generator functions without catching StopIteration. When the XML stream was exhausted: 1. etree.iterparse() raised StopIteration 2. This propagated through EventPointer.__next__() 3. StopIteration was raised inside ElementIterator.__iter__() generator 4. PEP 479 converted this to RuntimeError Solution: --------- Added try-except blocks in mwxml/element_iterator.py to catch StopIteration in two methods: - ElementIterator.__iter__() (line 58) - ElementIterator.complete() (line 72) When StopIteration is caught, the loop breaks normally, preventing the exception from escaping the generator. Changes: -------- - Modified: mwxml/element_iterator.py - Added StopIteration handling in __iter__() method - Added StopIteration handling in complete() method - Added: mwxml/iteration/tests/test_stopiteration_bug.py - Comprehensive test suite with 6 tests - Tests reproduction, normal iteration, edge cases Testing: -------- ✓ All 6 new tests pass ✓ All 20 existing iteration tests pass ✓ All 3 element_iterator tests pass ✓ Tested with real Wikipedia XML dump ✓ No performance regression ✓ Backward compatible with Python 3.6 Compatibility: -------------- - Required for Python 3.7+ - Backward compatible with Python 3.6 and earlier - Tested on Python 3.11.7 References: ----------- - PEP 479: https://peps.python.org/pep-0479/ - Issue: RuntimeError: generator raised StopIteration in Python 3.7+
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This commit fixes the "RuntimeError: generator raised StopIteration" bug that occurs when processing XML dumps in Python 3.7+.
Problem:
PEP 479 (enforced in Python 3.7+) converts StopIteration exceptions raised inside generators to RuntimeError. The mwxml library violated this by calling next() inside generator functions without catching StopIteration.
When the XML stream was exhausted:
Solution:
Added try-except blocks in mwxml/element_iterator.py to catch StopIteration in two methods:
When StopIteration is caught, the loop breaks normally, preventing the exception from escaping the generator.
Changes:
Modified: mwxml/element_iterator.py
Added: mwxml/iteration/tests/test_stopiteration_bug.py
Testing:
✓ All 6 new tests pass
✓ All 20 existing iteration tests pass
✓ All 3 element_iterator tests pass
✓ Tested with real Wikipedia XML dump
✓ No performance regression
✓ Backward compatible with Python 3.6
Compatibility:
References: