⚡️ Speed up function _quarterly_finder by 10%

[codeflash-ai]

📄 10% (0.10x) speedup for _quarterly_finder in pandas/plotting/_matplotlib/converter.py

⏱️ Runtime : 970 microseconds → 885 microseconds (best of 9 runs)

📝 Explanation and details

The optimization achieves a 9% speedup through several key improvements:

1. Direct Return Statements

• Replaced tuple assignments with direct returns in _get_default_annual_spacing() (e.g., return (1, 2) instead of (min_spacing, maj_spacing) = (1, 2); return (min_spacing, maj_spacing))
• This eliminates unnecessary variable creation and assignment overhead

2. Streamlined Conditional Logic

• In has_level_label(), extracted size = label_flags.size to avoid repeated attribute access
• Simplified the return logic by removing the redundant else branch

3. Optimized Array Operations in _quarterly_finder()

• Used bytes literals (b"Q%q") instead of strings for numpy structured array assignments, avoiding string-to-bytes conversion overhead for the "|S8" dtype
• Removed unnecessary info["fmt"] = "" assignment since zero-initialized structured arrays already have empty string fields
• Used more descriptive variable names (vmin_i, vmax_i) and intermediate variables for better code clarity

4. Reduced Redundant ppd Initialization

• Moved ppd = -1 assignments closer to where they're needed instead of initializing once at the top, though this has minimal performance impact

These optimizations are particularly effective for:

• Frequent function calls where tuple creation overhead adds up
• Large arrays where byte string operations and avoiding redundant assignments matter
• Plotting operations that repeatedly call these functions during tick formatting

The improvements focus on micro-optimizations that reduce Python object creation and unnecessary operations while maintaining identical functionality.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	✅ 139 Passed
🌀 Generated Regression Tests	🔘 None Found
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	87.9%

⚙️ Existing Unit Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
plotting/test_converter.py::test_quarterly_finder	970μs	885μs	9.64%✅

To edit these changes git checkout codeflash/optimize-_quarterly_finder-mhbq5qtu and push.