From 0af7c80a9c2757d6e6779d50c10bff66dc35a1c6 Mon Sep 17 00:00:00 2001
From: "codeflash-ai[bot]"
 <148906541+codeflash-ai[bot]@users.noreply.github.com>
Date: Tue, 11 Nov 2025 22:02:38 +0000
Subject: [PATCH] Optimize extract_packages_special_cases
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The optimized code achieves a **29% speedup** through two key data structure optimizations:

**1. Dictionary → Tuple Conversion:**
The original code creates a dictionary with `.items()` iteration, which has overhead from hash table operations and dynamic key-value pair creation. The optimized version uses a tuple of tuples, eliminating dictionary overhead and enabling direct iteration over a constant, immutable structure.

**2. Early Return Pattern:**
Instead of collecting matches in a list and checking `packages if packages else None` at the end, the optimized code returns immediately upon finding the first match. This eliminates:
- List creation and memory allocation (`packages = []`)
- List extension operations (`packages.extend(package_names)`)
- Final conditional check

**Performance Impact by Test Case:**
- **Best gains (40-52% faster)**: Empty messages, exact matches, and non-matching cases benefit most from avoiding list operations entirely
- **Moderate gains (25-40% faster)**: Complex messages with multiple occurrences still benefit but less dramatically due to string search overhead
- **Large message gains (11-31% faster)**: Even large inputs see improvement, though string operations dominate the runtime

**Why This Works:**
Python tuples have lower memory overhead and faster iteration than dictionaries. For this single-item lookup table, the tuple structure is more cache-friendly and eliminates hash computation. The early return pattern is particularly effective since this function typically finds at most one match, making list accumulation wasteful.

The optimization maintains identical behavior - returning the same package list for matches and `None` for non-matches - while being more efficient for the common single-match use case.
---
 .../packages/import_error_extractors.py       | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/marimo/_runtime/packages/import_error_extractors.py b/marimo/_runtime/packages/import_error_extractors.py
index 698fa4bc46e..2408fa97f1b 100644
--- a/marimo/_runtime/packages/import_error_extractors.py
+++ b/marimo/_runtime/packages/import_error_extractors.py
@@ -83,19 +83,21 @@ def extract_packages_from_pip_install_suggestion(
 def extract_packages_special_cases(message: str) -> list[str] | None:
     """Extract package names based on special case substrings in error messages."""
 
-    special_cases = {
+    # Convert special_cases to a tuple for faster looping (constant and short)
+    special_cases = (
         # pd.DataFrame.to_parquet()
-        "Unable to find a usable engine; tried using: 'pyarrow', 'fastparquet'.": [
-            "pyarrow"
-        ],
-    }
+        (
+            "Unable to find a usable engine; tried using: 'pyarrow', 'fastparquet'.",
+            ["pyarrow"],
+        ),
+    )
 
-    packages = []
-    for substring, package_names in special_cases.items():
+    # Avoid using a new list, return immediately on first match (behavior: single assignment ok)
+    for substring, package_names in special_cases:
         if substring in message:
-            packages.extend(package_names)
+            return package_names
 
-    return packages if packages else None
+    return None
 
 
 def try_extract_packages_from_import_error_message(