diff options
Diffstat (limited to 'Lib/string.py')
| -rw-r--r-- | Lib/string.py | 56 |
1 files changed, 48 insertions, 8 deletions
diff --git a/Lib/string.py b/Lib/string.py index b57c79b75e..ef0787f52b 100644 --- a/Lib/string.py +++ b/Lib/string.py @@ -94,7 +94,11 @@ class Template(metaclass=_TemplateMetaclass): raise ValueError('Invalid placeholder in string: line %d, col %d' % (lineno, colno)) - def substitute(self, *args, **kws): + def substitute(*args, **kws): + if not args: + raise TypeError("descriptor 'substitute' of 'Template' object " + "needs an argument") + self, *args = args # allow the "self" keyword be passed if len(args) > 1: raise TypeError('Too many positional arguments') if not args: @@ -120,7 +124,11 @@ class Template(metaclass=_TemplateMetaclass): self.pattern) return self.pattern.sub(convert, self.template) - def safe_substitute(self, *args, **kws): + def safe_substitute(*args, **kws): + if not args: + raise TypeError("descriptor 'safe_substitute' of 'Template' object " + "needs an argument") + self, *args = args # allow the "self" keyword be passed if len(args) > 1: raise TypeError('Too many positional arguments') if not args: @@ -160,16 +168,29 @@ class Template(metaclass=_TemplateMetaclass): # The field name parser is implemented in _string.formatter_field_name_split class Formatter: - def format(self, format_string, *args, **kwargs): + def format(*args, **kwargs): + if not args: + raise TypeError("descriptor 'format' of 'Formatter' object " + "needs an argument") + self, *args = args # allow the "self" keyword be passed + try: + format_string, *args = args # allow the "format_string" keyword be passed + except ValueError: + if 'format_string' in kwargs: + format_string = kwargs.pop('format_string') + else: + raise TypeError("format() missing 1 required positional " + "argument: 'format_string'") from None return self.vformat(format_string, args, kwargs) def vformat(self, format_string, args, kwargs): used_args = set() - result = self._vformat(format_string, args, kwargs, used_args, 2) + result, _ = self._vformat(format_string, args, kwargs, used_args, 2) self.check_unused_args(used_args, args, kwargs) return result - def _vformat(self, format_string, args, kwargs, used_args, recursion_depth): + def _vformat(self, format_string, args, kwargs, used_args, recursion_depth, + auto_arg_index=0): if recursion_depth < 0: raise ValueError('Max string recursion exceeded') result = [] @@ -185,6 +206,23 @@ class Formatter: # this is some markup, find the object and do # the formatting + # handle arg indexing when empty field_names are given. + if field_name == '': + if auto_arg_index is False: + raise ValueError('cannot switch from manual field ' + 'specification to automatic field ' + 'numbering') + field_name = str(auto_arg_index) + auto_arg_index += 1 + elif field_name.isdigit(): + if auto_arg_index: + raise ValueError('cannot switch from manual field ' + 'specification to automatic field ' + 'numbering') + # disable auto arg incrementing, if it gets + # used later on, then an exception will be raised + auto_arg_index = False + # given the field_name, find the object it references # and the argument it came from obj, arg_used = self.get_field(field_name, args, kwargs) @@ -194,13 +232,15 @@ class Formatter: obj = self.convert_field(obj, conversion) # expand the format spec, if needed - format_spec = self._vformat(format_spec, args, kwargs, - used_args, recursion_depth-1) + format_spec, auto_arg_index = self._vformat( + format_spec, args, kwargs, + used_args, recursion_depth-1, + auto_arg_index=auto_arg_index) # format the object and append to the result result.append(self.format_field(obj, format_spec)) - return ''.join(result) + return ''.join(result), auto_arg_index def get_value(self, key, args, kwargs): |