⚡️ Speed up method IndexVariable._data_equals by 122%

[codeflash-ai]

📄 122% (1.22x) speedup for IndexVariable._data_equals in xarray/core/variable.py

⏱️ Runtime : 8.54 milliseconds → 3.84 milliseconds (best of 19 runs)

📝 Explanation and details

The optimization achieves a 122% speedup through two key improvements to the IndexVariable class:

1. Fast-path _data_equals method:

• Original: Always calls _to_index() on both objects, which creates new pandas Index objects and handles name formatting
• Optimized: Directly compares the underlying arrays via self._data.array.equals(other._data.array) first, falling back to the original logic only on exceptions
• Why faster: Avoids the overhead of index creation and name processing for the common case where arrays can be compared directly

2. Conditional operations in _to_index:

• Original: Always processes MultiIndex names using list comprehension and always calls set_names()
• Optimized:
  • Uses any(name is None for name in names) to check if name processing is needed
  • Only creates new names when there are actually None values to replace
  • Uses tuple comprehension instead of list comprehension (slight memory efficiency)
  • Only calls set_names() when the name actually differs from self.name

Why these optimizations matter:

• IndexVariable objects are frequently compared during xarray operations like merging, alignment, and coordinate handling
• The _to_index() method is called whenever pandas Index objects need to be created, which happens during many coordinate operations
• By avoiding unnecessary object creation and string formatting when the existing state is already correct, the code eliminates redundant work

Performance characteristics:

• Best gains when comparing identical IndexVariable objects or when MultiIndex names are already properly set
• Maintains full backward compatibility and error handling
• The try/except pattern in _data_equals ensures robustness while optimizing the common path

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	🔘 None Found
⏪ Replay Tests	✅ 255 Passed
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

⏪ Replay Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
test_pytest_xarrayteststest_concat_py_xarrayteststest_computation_py_xarrayteststest_formatting_py_xarray__replay_test_0.py::test_xarray_core_variable_IndexVariable__data_equals	5.42ms	2.14ms	153%✅

To edit these changes git checkout codeflash/optimize-IndexVariable._data_equals-miiuopnw and push.