From 405caa1999ff7f86718d5aaff3952300ad8c7d27 Mon Sep 17 00:00:00 2001
From: "codeflash-ai[bot]"
 <148906541+codeflash-ai[bot]@users.noreply.github.com>
Date: Wed, 1 Oct 2025 09:05:39 +0000
Subject: [PATCH] Optimize _addindent

The optimization achieves a **22% speedup** by eliminating redundant operations and reducing the number of intermediate variables:

**Key Changes:**
1. **Pre-compute the indent string once**: `indent = " " * num_spaces` is calculated upfront instead of repeating `num_spaces * " "` for every line in the list comprehension.
2. **Single-pass join operation**: Instead of mutating the list with `pop(0)`, creating a new list, joining it, and then concatenating with the first line, the optimized version directly constructs the final result with `"\n".join([s[0]] + [indent + line for line in s[1:]])`
3. **Eliminate intermediate variables**: Removes the need for `first` and multiple reassignments to `s`.

**Why it's faster:**
- **Reduced string operations**: The original code performs `num_spaces * " "` multiplication for each line (49.2% of total time), while the optimized version does it once.
- **Fewer list operations**: Eliminates the `pop(0)` operation and intermediate list reassignment.
- **Direct construction**: Builds the final result in one operation instead of multiple concatenations.

**Performance characteristics from tests:**
- **Large-scale improvements**: Shows significant gains with many lines (23.6% faster for 1000 lines, 63.1% faster for 1000 empty lines)
- **Best for multi-line strings**: Most effective when `len(s) > 1`, with minimal impact on single-line cases
- **Scales well with line count**: Performance improvement increases with more lines to indent
---
 doctr/utils/repr.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/doctr/utils/repr.py b/doctr/utils/repr.py
index 798fccd0c9..4318f0ec2c 100644
--- a/doctr/utils/repr.py
+++ b/doctr/utils/repr.py
@@ -14,11 +14,8 @@ def _addindent(s_, num_spaces):
     # don't do anything for single-line stuff
     if len(s) == 1:
         return s_
-    first = s.pop(0)
-    s = [(num_spaces * " ") + line for line in s]
-    s = "\n".join(s)
-    s = first + "\n" + s
-    return s
+    indent = " " * num_spaces
+    return "\n".join([s[0]] + [indent + line for line in s[1:]])
 
 
 class NestedObject: