Return the tuple (major, minor, patch) version extracted from the str.

def _str_to_version(version_str, allow_wildcard=False):
  """Return the tuple (major, minor, patch) version extracted from the str."""
  reg = _VERSION_WILDCARD_REG if allow_wildcard else _VERSION_RESOLVED_REG
  res = reg.match(version_str)
  if not res:
    msg = "Invalid version '{}'. Format should be x.y.z".format(version_str)
    if allow_wildcard:
      msg += " with {x,y,z} being digits or wildcard."
    else:
      msg += " with {x,y,z} being digits."
    raise ValueError(msg)
  return tuple(
      v if v == "*" else int(v)
      for v in [res.group("major"), res.group("minor"), res.group("patch")])