diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
index 48d1bde..e1ba390 100644
--- a/.github/workflows/python-app.yml
+++ b/.github/workflows/python-app.yml
@@ -30,10 +30,11 @@ jobs:
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
     - name: Test with pytest
       run: |
-        pytest --continue-on-collection-errors
+        git fetch --no-tags --prune --depth=1 origin +refs/heads/*:refs/remotes/origin/*
+        git diff origin/main HEAD --name-only -- practice | xargs dirname | sort | uniq | xargs pytest
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names
         flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
         # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
-        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
\ No newline at end of file
diff --git a/practice/diamond/diamond.py b/practice/diamond/diamond.py
index 14f2850..4b6bb0e 100644
--- a/practice/diamond/diamond.py
+++ b/practice/diamond/diamond.py
@@ -1,2 +1,25 @@
 def rows(letter):
-    pass
+    rows = []
+    size = 2 * (ord(letter) - ord('A')) + 1 # size of the diamond
+
+    for i in range(size): # iterate over the rows
+        row = ' ' * abs(size // 2 - i) # spaces before the first letter
+        row += chr(ord('A') + min(i, size - i - 1)) # first letter
+    
+        if i != 0 and i != size - 1:  # middle row
+           row += ' ' * (2 * min(i, size - i - 1) - 1) # spaces between the letters
+           row += chr(ord('A') + min(i, size - i - 1)) # second letter
+        
+        row += ' ' * abs(size // 2 - i) # spaces after the second letter
+        rows.append(row) # add the row to the list
+
+    return rows
+
+pass
+
+# My Understanding of the pattern --->
+# It starts with the letter 'A' at the top and goes up to the input letter, then back down to 'A'. 
+# Each row of the diamond has two same letters, except for the first and last rows which have one letter
+# The letters are separated by spaces, and the number of spaces between the letters increases by two with each row 
+# from the top to the middle, then decreases by two with each row from the middle to the bottom.
+