run black on codebase

repl.py

@@ -1,12 +1,12 @@
 from ziffers import *
 from rich import print
 
-EXIT_CONDITION = ('exit', 'quit', '')
+EXIT_CONDITION = ("exit", "quit", "")
 
 if __name__ == "__main__":
     print(f"[purple]== ZIFFERS REPL ==[/purple]")
     while True:
-        expr = input('> ')
+        expr = input("> ")
         if expr not in EXIT_CONDITION:
             try:
                 result = parse_expression(expr)