Merge pull request cs50#207 from cs50/curiouskiwi-plates

Update plates check

plates/__init__.py

@@ -13,7 +13,9 @@ def test_cs50():
     """input of CS50 yields output of Valid"""
     input = "CS50"
     output = "Valid"
-    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(regex(output), output, regex=True).exit()
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
 
 
 # Ready Player One
@@ -22,7 +24,9 @@ def test_ECTO88():
     """input of ECTO88 yields output of Valid"""
     input = "ECTO88"
     output = "Valid"
-    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(regex(output), output, regex=True).exit()
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
 
 
 # Ferris Buehler's Day Off
@@ -31,7 +35,9 @@ def test_NRVOUS():
     """input of NRVOUS yields output of Valid"""
     input = "NRVOUS"
     output = "Valid"
-    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(regex(output), output, regex=True).exit()
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
 
 
 # Tests for Zero as first number
@@ -40,16 +46,31 @@ def test_CS05():
     """input of CS05 yields output of Invalid"""
     input = "CS05"
     output = "Invalid"
-    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(regex(output), output, regex=True).exit()
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
+
+
+# First two chars are not letters
+@check50.check(exists)
+def test_50():
+    """input of 50 yields output of Invalid"""
+    input = "50"
+    output = "Invalid"
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
+
 
-
 # Numbers before letters (after the first 2 letters)
 @check50.check(exists)
 def test_CS50P2():
     """input of CS50P2 yields output of Invalid"""
     input = "CS50P2"
     output = "Invalid"
-    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(regex(output), output, regex=True).exit()
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
 
 
 # Non-alphanumeric characters (after the first 2 letters)
@@ -58,7 +79,9 @@ def test_PI3_14():
     """input of PI3.14 yields output of Invalid"""
     input = "PI3.14"
     output = "Invalid"
-    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(regex(output), output, regex=True).exit()
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
 
 
 # Length (too short)
@@ -67,7 +90,9 @@ def test_445108():
     """input of H yields output of Invalid"""
     input = "H"
     output = "Invalid"
-    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(regex(output), output, regex=True).exit()
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
 
 
 # Length (too long) (Back to the Future)
@@ -76,9 +101,11 @@ def test_OUTATIME():
     """input of OUTATIME yields output of Invalid"""
     input = "OUTATIME"
     output = "Invalid"
-    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(regex(output), output, regex=True).exit()
+    check50.run("python3 plates.py").stdin(input, prompt=True).stdout(
+        regex(output), output, regex=True
+    ).exit()
 
 
 def regex(text):
     """match case-insensitively, allowing for only spaces on either side"""
-    return fr'(?i)^\s*{escape(text)}\s*$'
+    return rf"(?i)^\s*{escape(text)}\s*$"