gh-104683: Modernise clinic.py using str.removeprefix and str.removesuffix

Tools/clinic/clinic.py

@@ -1747,7 +1747,7 @@ def is_stop_line(line):
  # make sure to recognize stop line even if it
  # doesn't end with EOL (it could be the very end of the file)
  if line.startswith(stop_line):
- remainder = line[len(stop_line):]
+ remainder = line.removeprefix(stop_line)
  if remainder and not remainder.isspace():
  fail(f"Garbage after stop line:{remainder!r}")
  return True
@@ -1765,7 +1765,7 @@ def is_stop_line(line):
  if body_prefix:
  line = line.lstrip()
  assert line.startswith(body_prefix)
- line = line[len(body_prefix):]
+ line = line.removeprefix(body_prefix)
  input_add(line)
 
  # consume output and checksum line, if present.
@@ -2570,7 +2570,7 @@ def add_c_converter(f, name=None):
  name = f.__name__
  if not name.endswith('_converter'):
  return f
- name = name[:-len('_converter')]
+ name = name.removesuffix('_converter')
  converters[name] = f
  return f
 
@@ -3977,7 +3977,7 @@ def add_c_return_converter(f, name=None):
  name = f.__name__
  if not name.endswith('_return_converter'):
  return f
- name = name[:-len('_return_converter')]
+ name = name.removesuffix('_return_converter')
  return_converters[name] = f
  return f
 
@@ -5369,7 +5369,7 @@ def main(argv):
  if name in ignored:
  continue
  if name.endswith(suffix):
- ids.append((name, name[:-len(suffix)]))
+ ids.append((name, name.removesuffix(suffix)))
  break
  print()