autoblack: actions/checkout@v1 # Use v1, NOT v2

.github/workflows/autoblack.yml

@@ -9,7 +9,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v1  # Use v1, NOT v2
       - uses: actions/setup-python@v1
       - run: pip install black
       - run: black --check .

ciphers/rot13.py

@@ -1,4 +1,4 @@
-def dencrypt(s: str, n: int=13):
+def dencrypt(s: str, n: int = 13):
     """
     https://en.wikipedia.org/wiki/ROT13
 
@@ -24,13 +24,14 @@ def main():
     s0 = input("Enter message: ")
 
     s1 = dencrypt(s0, 13)
-    print("Encryption:", s1)  
+    print("Encryption:", s1)
 
     s2 = dencrypt(s1, 13)
-    print("Decryption: ", s2)  
+    print("Decryption: ", s2)
 
 
 if __name__ == "__main__":
     import doctest
+
     doctest.testmod()
     main()

sorts/comb_sort.py

@@ -54,6 +54,7 @@ def comb_sort(data: list) -> list:
 
 if __name__ == "__main__":
     import doctest
+
     doctest.testmod()
 
     user_input = input("Enter numbers separated by a comma:\n").strip()