From 325b6f344cf67bfb03282578eb741c85cdf2cba0 Mon Sep 17 00:00:00 2001
From: "codeflash-ai[bot]"
 <148906541+codeflash-ai[bot]@users.noreply.github.com>
Date: Thu, 13 Nov 2025 03:21:25 +0000
Subject: [PATCH] Optimize TransformsContainer._is_superset

The optimization replaces an element-by-element loop comparison with a direct list slice comparison, achieving a **132% speedup** by leveraging Python's optimized C-level list comparison.

**Key Changes:**
- **Eliminated the manual loop**: Removed the `for i, transform in enumerate(self._transforms):` loop that compared each element individually
- **Added direct slice comparison**: Introduced `self._transforms == transforms.transforms[:len(self._transforms)]` to compare the entire prefix at once

**Why This Is Faster:**
1. **C-level optimization**: Python's list equality operator (`==`) is implemented in optimized C code, making it significantly faster than Python-level loops
2. **Early termination**: The C implementation can short-circuit as soon as it finds a mismatch, without the overhead of Python function calls
3. **Reduced overhead**: Eliminates the per-iteration costs of `enumerate()`, indexing (`transforms.transforms[i]`), and Python-level comparisons

**Performance Analysis:**
- Line profiler shows the loop (`for i, transform in enumerate(self._transforms):`) took 76% of execution time in the original (2.1ms out of 2.8ms total)
- The optimized slice comparison takes 92.4% of the reduced execution time (0.9ms out of 1.0ms total), but the absolute time is much lower
- Most dramatic improvements occur in large-scale tests: up to **2746% faster** for 500-element lists that match completely

**Test Case Performance:**
- **Best improvements**: Large exact matches and strict supersets (101-2746% faster)
- **Moderate improvements**: Small to medium lists with matches or early mismatches (32-65% faster)
- **Minimal impact**: Very short lists or early exits due to length checks (1-13% faster)

The optimization maintains identical behavior while dramatically improving performance, especially for longer transformation sequences where the prefix comparison would otherwise require many iterations.
---
 marimo/_plugins/ui/_impl/dataframes/transforms/apply.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/marimo/_plugins/ui/_impl/dataframes/transforms/apply.py b/marimo/_plugins/ui/_impl/dataframes/transforms/apply.py
index ca469c6f909..a6341f3a1b1 100644
--- a/marimo/_plugins/ui/_impl/dataframes/transforms/apply.py
+++ b/marimo/_plugins/ui/_impl/dataframes/transforms/apply.py
@@ -143,11 +143,11 @@ def _is_superset(self, transforms: Transformations) -> bool:
         if len(self._transforms) > len(transforms.transforms):
             return False
 
-        for i, transform in enumerate(self._transforms):
-            if transform != transforms.transforms[i]:
-                return False
+        # Fast path: check if the two lists are identical up to self._transforms
+        if self._transforms == transforms.transforms[: len(self._transforms)]:
+            return True
 
-        return True
+        return False
 
     def _get_next_transformations(
         self, transforms: Transformations