Update python.gram

Author: sharktide

Grammar/python.gram

@@ -1259,7 +1259,7 @@ invalid_parameters:
     | (slash_no_default | slash_with_default) param_maybe_default* a='/' {
         RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ may appear only once") }
     | slash_no_default? param_no_default* invalid_parameters_helper a=param_no_default {
-        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "parameter without a default follows parameter with a default") }
+        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "positional parameter without a default follows parameter with a default") }
     | param_no_default* a='(' param_no_default+ ','? b=')' {
         RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "Function parameters cannot be parenthesized") }
     | (slash_no_default | slash_with_default)? param_maybe_default* '*' (',' | param_no_default) param_maybe_default* a='/' {
@@ -1287,7 +1287,7 @@ invalid_lambda_parameters:
     | (lambda_slash_no_default | lambda_slash_with_default) lambda_param_maybe_default* a='/' {
         RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ may appear only once") }
     | lambda_slash_no_default? lambda_param_no_default* invalid_lambda_parameters_helper a=lambda_param_no_default {
-        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "parameter without a default follows parameter with a default") }
+        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "positional parameter without a default follows parameter with a default") }
     | lambda_param_no_default* a='(' ','.lambda_param+ ','? b=')' {
         RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "Lambda expression parameters cannot be parenthesized") }
     | (lambda_slash_no_default | lambda_slash_with_default)? lambda_param_maybe_default* '*' (',' | lambda_param_no_default) lambda_param_maybe_default* a='/' {