python
diff --git a/‎Tools/clinic/clinic.py‎
Lines changed: 30 additions & 26 deletions b/‎Tools/clinic/clinic.py‎
Lines changed: 30 additions & 26 deletions
diff --git a/‎Tools/clinic/cpp.py‎
Lines changed: 1 addition & 1 deletion b/‎Tools/clinic/cpp.py‎
Lines changed: 1 addition & 1 deletion
@@ -208,7 +208,7 @@ def is_legal_py_identifier(s: str) -> bool:
 def ensure_legal_c_identifier(s: str) -> str:
     # for now, just complain if what we're given isn't legal
     if not is_legal_c_identifier(s):
-        fail("Illegal C identifier: {}".format(s))
+        fail("Illegal C identifier:", s)
     # but if we picked a C keyword, pick something else
     if s in c_keywords:
         return s + "_value"
@@ -991,7 +991,7 @@ def parser_body(prototype, *fields, declarations=''):
                 argname_fmt = 'PyTuple_GET_ITEM(args, %d)'
 
 
-            left_args = "{} - {}".format(nargs, max_pos)
+            left_args = f"{nargs} - {max_pos}"
             max_args = NO_VARARG if (vararg != NO_VARARG) else max_pos
             parser_code = [normalize_snippet("""
                 if (!_PyArg_CheckPositional("{name}", %s, %d, %s)) {{
@@ -1435,7 +1435,7 @@ def render_function(self, clinic, f):
                 first_optional = min(first_optional, i)
 
             if p.is_vararg():
-                data.cleanup.append("Py_XDECREF({});".format(c.parser_name))
+                data.cleanup.append(f"Py_XDECREF({c.parser_name});")
 
             # insert group variable
             group = p.group
@@ -1487,8 +1487,7 @@ def render_function(self, clinic, f):
 
         template_dict['c_basename'] = c_basename
 
-        methoddef_name = "{}_METHODDEF".format(c_basename.upper())
-        template_dict['methoddef_name'] = methoddef_name
+        template_dict['methoddef_name'] = c_basename.upper() + "_METHODDEF"
 
         template_dict['docstring'] = self.docstring_for_c_string(f)
 
@@ -1791,7 +1790,7 @@ def is_stop_line(line):
             for field in shlex.split(arguments):
                 name, equals, value = field.partition('=')
                 if not equals:
-                    fail("Mangled Argument Clinic marker line: {!r}".format(line))
+                    fail("Mangled Argument Clinic marker line:", repr(line))
                 d[name.strip()] = value.strip()
 
             if self.verify:
@@ -1867,7 +1866,10 @@ def print_block(self, block, *, core_includes=False):
                 output += '\n'
             write(output)
 
-        arguments="output={} input={}".format(compute_checksum(output, 16), compute_checksum(input, 16))
+        arguments = "output={output} input={input}".format(
+            output=compute_checksum(output, 16),
+            input=compute_checksum(input, 16)
+        )
         write(self.language.checksum_line.format(dsl_name=dsl_name, arguments=arguments))
         write("\n")
 
@@ -1976,7 +1978,7 @@ def dump(self):
 def file_changed(filename: str, new_contents: str) -> bool:
     """Return true if file contents changed (meaning we must update it)"""
     try:
-        with open(filename, 'r', encoding="utf-8") as fp:
+        with open(filename, encoding="utf-8") as fp:
             old_contents = fp.read()
         return old_contents != new_contents
     except FileNotFoundError:
@@ -2132,7 +2134,7 @@ def parse(self, input):
             dsl_name = block.dsl_name
             if dsl_name:
                 if dsl_name not in self.parsers:
-                    assert dsl_name in parsers, "No parser to handle {!r} block.".format(dsl_name)
+                    assert dsl_name in parsers, f"No parser to handle {dsl_name!r} block."
                     self.parsers[dsl_name] = parsers[dsl_name](self)
                 parser = self.parsers[dsl_name]
                 try:
@@ -2172,7 +2174,7 @@ def parse(self, input):
                                      "can't make directory {}!".format(
                                         destination.filename, dirname))
                         if self.verify:
-                            with open(destination.filename, "rt") as f:
+                            with open(destination.filename) as f:
                                 parser_2 = BlockParser(f.read(), language=self.language)
                                 blocks = list(parser_2)
                                 if (len(blocks) != 1) or (blocks[0].input != 'preserve\n'):
@@ -2239,7 +2241,7 @@ def parse_file(
     except KeyError:
         fail("Can't identify file type for file " + repr(filename))
 
-    with open(filename, 'r', encoding="utf-8") as f:
+    with open(filename, encoding="utf-8") as f:
         raw = f.read()
 
     # exit quickly if there are no clinic markers in the file
@@ -2537,9 +2539,9 @@ def get_displayname(self, i):
         if i == 0:
             return '"argument"'
         if not self.is_positional_only():
-            return '''"argument '{}'"'''.format(self.name)
+            return f'"argument {self.name!r}"'
         else:
-            return '"argument {}"'.format(i)
+            return f'"argument {i}"'
 
 
 class LandMine:
@@ -2723,7 +2725,8 @@ def __init__(self,
                 if isinstance(self.default_type, type):
                     types_str = self.default_type.__name__
                 else:
-                    types_str = ', '.join((cls.__name__ for cls in self.default_type))
+                    names = [cls.__name__ for cls in self.default_type]
+                    types_str = ', '.join(names)
                 fail("{}: default value {!r} for field {} is not of type {}".format(
                     self.__class__.__name__, default, name, types_str))
             self.default = default
@@ -3955,7 +3958,7 @@ def set_template_dict(self, template_dict):
                               ' Py_TYPE({0})->tp_new == base_tp->tp_new)'
                              ).format(self.name)
 
-            line = '{} &&\n        '.format(type_check)
+            line = f'{type_check} &&\n        '
             template_dict['self_type_check'] = line
 
             type_object = self.function.cls.type_object
@@ -4011,10 +4014,12 @@ def declare(self, data):
         data.return_value = data.converter_retval
 
     def err_occurred_if(self, expr, data):
-        data.return_conversion.append('if (({}) && PyErr_Occurred()) {{\n    goto exit;\n}}\n'.format(expr))
+        line = f'if (({expr}) && PyErr_Occurred()) {{\n    goto exit;\n}}\n'
+        data.return_conversion.append(line)
 
     def err_occurred_if_null_pointer(self, variable, data):
-        data.return_conversion.append('if ({} == NULL) {{\n    goto exit;\n}}\n'.format(variable))
+        line = f'if ({variable} == NULL) {{\n    goto exit;\n}}\n'
+        data.return_conversion.append(line)
 
     def render(self, function, data):
         """
@@ -4477,13 +4482,13 @@ def state_modulename_name(self, line):
         c_basename = c_basename.strip() or None
 
         if not is_legal_py_identifier(full_name):
-            fail("Illegal function name: {}".format(full_name))
+            fail("Illegal function name:", full_name)
         if c_basename and not is_legal_c_identifier(c_basename):
-            fail("Illegal C basename: {}".format(c_basename))
+            fail("Illegal C basename:", c_basename)
 
         return_converter = None
         if returns:
-            ast_input = "def x() -> {}: pass".format(returns)
+            ast_input = f"def x() -> {returns}: pass"
             module = None
             try:
                 module = ast.parse(ast_input)
@@ -4696,15 +4701,15 @@ def state_parameter(self, line):
 
         module = None
         try:
-            ast_input = "def x({}): pass".format(base)
+            ast_input = f"def x({base}): pass"
             module = ast.parse(ast_input)
         except SyntaxError:
             try:
                 # the last = was probably inside a function call, like
                 #   c: int(accept={str})
                 # so assume there was no actual default value.
                 default = None
-                ast_input = "def x({}): pass".format(line)
+                ast_input = f"def x({line}): pass"
                 module = ast.parse(ast_input)
             except SyntaxError:
                 pass
@@ -4748,8 +4753,7 @@ def state_parameter(self, line):
                 self.parameter_state = self.ps_optional
             default = default.strip()
             bad = False
-            ast_input = "x = {}".format(default)
-            bad = False
+            ast_input = f"x = {default}"
             try:
                 module = ast.parse(ast_input)
 
@@ -4856,7 +4860,7 @@ def bad_node(self, node):
         dict = legacy_converters if legacy else converters
         legacy_str = "legacy " if legacy else ""
         if name not in dict:
-            fail('{} is not a valid {}converter'.format(name, legacy_str))
+            fail(f'{name} is not a valid {legacy_str}converter')
         # if you use a c_name for the parameter, we just give that name to the converter
         # but the parameter object gets the python name
         converter = dict[name](c_name or parameter_name, parameter_name, self.function, value, **kwargs)
@@ -5388,7 +5392,7 @@ def main(argv):
                 for parameter_name, parameter in signature.parameters.items():
                     if parameter.kind == inspect.Parameter.KEYWORD_ONLY:
                         if parameter.default != inspect.Parameter.empty:
-                            s = '{}={!r}'.format(parameter_name, parameter.default)
+                            s = f'{parameter_name}={parameter.default!r}'
                         else:
                             s = parameter_name
                         parameters.append(s)
 
@@ -185,7 +185,7 @@ def pop_stack() -> TokenAndCondition:
 
 if __name__ == '__main__':
     for filename in sys.argv[1:]:
-        with open(filename, "rt") as f:
+        with open(filename) as f:
             cpp = Monitor(filename, verbose=True)
             print()
             print(filename)