Refactor residual .format()s to f-strings. (#32)

Replace .format() with f-string in ast.py and lexer.py.

Author: changeling

graphql/language/ast.py

@@ -83,7 +83,7 @@ def __str__(self):
 
     def __repr__(self):
         """Print a simplified form when appearing in repr() or inspect()."""
-        return "<Location {}:{}>".format(self.start, self.end)
+        return f"<Location {self.start}:{self.end}>"
 
     def __inspect__(self):
         return repr(self)

graphql/language/lexer.py

@@ -61,7 +61,7 @@ def __str__(self):
 
     def __repr__(self):
         """Print a simplified form when appearing in repr() or inspect()."""
-        return "<Token {} {}/{}>".format(self.desc, self.line, self.column)
+        return f"<Token {self.desc} {self.line}/{self.column}>"
 
     def __inspect__(self):
         return repr(self)