1 files changed, 85 insertions, 0 deletions
diff --git a/challenge-266/packy-anderson/python/ch-2.py b/challenge-266/packy-anderson/python/ch-2.py
new file mode 100644
index 0000000000..dc2c0393bc
--- /dev/null
+++ b/challenge-266/packy-anderson/python/ch-2.py
@@ -0,0 +1,85 @@
+#!/usr/bin/env python
+
+def isDiagonal(x, y, N):
+  return (
+    N == 1 or N == 2 or x == y or x + y == N - 1
+  )
+
+def isXMatrix(matrix):
+  N = len(matrix)
+  for y, row in enumerate(matrix):
+    for x, value in enumerate(row):
+      # fail if diagonal values are zero or
+      # non-diagonal values are non-zero
+      if isDiagonal(x, y, N) != (value != 0):
+        return False
+  return True
+
+def formatMatrix(matrix, indent=17):
+    output = []
+    for row in matrix:
+        output_row = ' ' * indent + '  ['
+        output_row += ', '.join(map(lambda i: str(i), row))
+        output_row += ']'
+        output.append(output_row)
+
+    return(
+        "[\n" + ",\n".join(output) + "\n" +
+        ' ' * indent + ']'
+    )
+
+def solution(matrix):
+    print(f'Input: $matrix = {formatMatrix(matrix)}')
+    print(f'Output: {isXMatrix(matrix)}')
+
+print('Example 1:')
+solution([
+  [1, 0, 0, 2],
+  [0, 3, 4, 0],
+  [0, 5, 6, 0],
+  [7, 0, 0, 1],
+])
+
+print('\nExample 2:')
+solution([
+  [1, 2, 3],
+  [4, 5, 6],
+  [7, 8, 9],
+])
+
+print('\nExample 3:')
+solution([
+  [1, 0, 2],
+  [0, 3, 0],
+  [4, 0, 5],
+])
+
+print('\nExample 4:')
+solution([
+  [1, 0, 0, 0, 1],
+  [0, 1, 0, 1, 0],
+  [0, 0, 1, 0, 0],
+  [0, 1, 0, 1, 0],
+  [1, 0, 0, 0, 1],
+])
+
+print('\nExample 5:')
+solution([
+  [1, 0, 1, 0, 1],
+  [0, 1, 0, 1, 0],
+  [0, 0, 1, 0, 0],
+  [0, 1, 0, 1, 0],
+  [1, 0, 0, 0, 1],
+])
+
+print('\nExample 6:')
+solution([
+  [1, 1],
+  [1, 1]
+])
+
+print('\nExample 7:')
+solution([
+  [1, 0],
+  [1, 1]
+])