1 files changed, 37 insertions, 0 deletions
diff --git a/challenge-317/sgreen/python/ch-2.py b/challenge-317/sgreen/python/ch-2.py
new file mode 100755
index 0000000000..b855287fdc
--- /dev/null
+++ b/challenge-317/sgreen/python/ch-2.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+
+from collections import Counter
+import sys
+
+
+def friendly_strings(str1: str, str2: str) -> bool:
+    # Check strings are the same length
+    if len(str1) != len(str2):
+        return False
+
+    if str1 == str2:
+        # We can still swap two characters if there are any letters that
+        #  appear two or more times
+        freq = Counter(str1)
+        return any(i for i in freq.values() if i > 1)
+
+    # Find characters that are different
+    differences = [ i for i in range(len(str1)) if str1[i] != str2[i]]
+
+    if len(differences) == 2:
+        # Check that the letters at each position were switched
+        pos1, pos2 = differences
+        if str1[pos1] == str2[pos2] and str2[pos1] == str1[pos2]:
+            return True
+
+    return False
+
+
+
+def main():
+    result = friendly_strings(sys.argv[1], sys.argv[2])
+    print(result)
+
+
+if __name__ == '__main__':
+    main()