From f87094e011b988c2193a634d34861e28cbd19e24 Mon Sep 17 00:00:00 2001
From: "exercism-solutions-syncer[bot]"
 <211797793+exercism-solutions-syncer[bot]@users.noreply.github.com>
Date: Sun, 12 Oct 2025 19:24:16 +0000
Subject: [PATCH 1/3] [Sync Iteration] python/diamond/1

---
 solutions/python/diamond/1/diamond.py | 39 +++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 solutions/python/diamond/1/diamond.py

diff --git a/solutions/python/diamond/1/diamond.py b/solutions/python/diamond/1/diamond.py
new file mode 100644
index 0000000..0fdf4fe
--- /dev/null
+++ b/solutions/python/diamond/1/diamond.py
@@ -0,0 +1,39 @@
+"""
+The diamond kata takes as its input a letter, and outputs it in
+a diamond shape. Given a letter, it prints a diamond starting
+with 'A', with the supplied letter at the widest point.
+"""
+
+import string
+
+CHARS: str = string.ascii_uppercase
+
+
+def rows(letter: str) -> list:
+    """
+    Return the diamond rows from 'A' to ``letter``.
+
+    Builds the upper half and mirrors it to form a symmetric diamond.
+
+    :param str letter: Uppercase letter (``'A'``-``'Z'``) marking the widest row.
+    :returns: The full diamond as a list of strings, one per row.
+    :rtype: list
+    :raises ValueError: If ``letter`` is not an ASCII uppercase character.
+    """
+    result: list = []
+    letter_index: int = CHARS.index(letter)
+    row_length: int = (letter_index * 2) + 1
+
+    for i, char in enumerate(CHARS[: letter_index + 1]):
+        # All rows have as many trailing spaces as leading spaces.
+        spaces: str = " " * (letter_index - i)
+        # The first/last row contains one 'A'.
+        if i == 0:
+            result.append(spaces + char + spaces)
+        else:
+            middle: str = " " * (row_length - 2 - (len(spaces) * 2))
+            # All rows, except the first and last, have exactly two identical letters.
+            result.append(spaces + char + middle + char + spaces)
+    # Mirror the list: the bottom half has the letters in descending order.
+    result = result + result[::-1][1:]
+    return result

From ed0afece4b71b748e7fec62273667f58e7f761df Mon Sep 17 00:00:00 2001
From: Egor Kostan <igorkostan@gmail.com>
Date: Sun, 12 Oct 2025 12:32:48 -0700
Subject: [PATCH 2/3] Update diamond.py
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add type hint for the return: -> list[str] to make it explicit.
In the middle calculation, len(spaces) could be avoided since spaces is a str of known length—use (letter_index - i) * 2 directly for tiny perf gain, but it's negligible.
Consider adding a check for letter == 'A' early to skip the loop if desired, but the current loop handles it fine.
---
 diamond/diamond.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/diamond/diamond.py b/diamond/diamond.py
index 8a39d1a..747c256 100644
--- a/diamond/diamond.py
+++ b/diamond/diamond.py
@@ -9,7 +9,7 @@
 CHARS: str = string.ascii_uppercase
 
 
-def rows(letter: str) -> list:
+def rows(letter: str) -> list[str]:
     """
     Return the diamond rows from 'A' to ``letter``.
 
@@ -26,12 +26,13 @@ def rows(letter: str) -> list:
 
     for i, char in enumerate(CHARS[: letter_index + 1]):
         # All rows have as many trailing spaces as leading spaces.
-        spaces: str = " " * (letter_index - i)
+        spaces_length: int = letter_index - i
+        spaces: str = " " * spaces_length
         # The first/last row contains one 'A'.
-        if i == 0:
+        if char == "A":
             result.append(spaces + char + spaces)
         else:
-            middle: str = " " * (row_length - 2 - (len(spaces) * 2))
+            middle: str = " " * (row_length - 2 - (spaces_length * 2))
             # All rows, except the first and last,
             # have exactly two identical letters.
             result.append(spaces + char + middle + char + spaces)

From 8f2c461701f6535b66d96ae6af485529f0772888 Mon Sep 17 00:00:00 2001
From: Egor Kostan <igorkostan@gmail.com>
Date: Sun, 12 Oct 2025 12:35:16 -0700
Subject: [PATCH 3/3] Update diamond.py

---
 diamond/diamond.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/diamond/diamond.py b/diamond/diamond.py
index 747c256..ea9d514 100644
--- a/diamond/diamond.py
+++ b/diamond/diamond.py
@@ -15,7 +15,8 @@ def rows(letter: str) -> list[str]:
 
     Builds the upper half and mirrors it to form a symmetric diamond.
 
-    :param str letter: Uppercase letter (``'A'``-``'Z'``) marking the widest row.
+    :param str letter: Uppercase letter (``'A'``-``'Z'``) marking the
+                       widest row.
     :returns: The full diamond as a list of strings, one per row.
     :rtype: list
     :raises ValueError: If ``letter`` is not an ASCII uppercase character.