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| """\ |
| The ``namedutils`` module defines two lightweight container types: |
| :class:`namedtuple` and :class:`namedlist`. Both are subtypes of built-in |
| sequence types, which are very fast and efficient. They simply add |
| named attribute accessors for specific indexes within themselves. |
| |
| The :class:`namedtuple` is identical to the built-in |
| :class:`collections.namedtuple`, with a couple of enhancements, |
| including a ``__repr__`` more suitable to inheritance. |
| |
| The :class:`namedlist` is the mutable counterpart to the |
| :class:`namedtuple`, and is much faster and lighter-weight than |
| full-blown :class:`object`. Consider this if you're implementing nodes |
| in a tree, graph, or other mutable data structure. If you want an even |
| skinnier approach, you'll probably have to look to C. |
| """ |
|
|
|
|
| import sys as _sys |
| from collections import OrderedDict |
| from keyword import iskeyword as _iskeyword |
| from operator import itemgetter as _itemgetter |
|
|
|
|
| __all__ = ['namedlist', 'namedtuple'] |
|
|
| |
|
|
| _repr_tmpl = '{name}=%r' |
|
|
| _imm_field_tmpl = '''\ |
| {name} = _property(_itemgetter({index:d}), doc='Alias for field {index:d}') |
| ''' |
|
|
| _m_field_tmpl = '''\ |
| {name} = _property(_itemgetter({index:d}), _itemsetter({index:d}), doc='Alias for field {index:d}') |
| ''' |
|
|
| |
| |
| |
|
|
| _namedtuple_tmpl = '''\ |
| class {typename}(tuple): |
| '{typename}({arg_list})' |
| |
| __slots__ = () |
| |
| _fields = {field_names!r} |
| |
| def __new__(_cls, {arg_list}): # TODO: tweak sig to make more extensible |
| 'Create new instance of {typename}({arg_list})' |
| return _tuple.__new__(_cls, ({arg_list})) |
| |
| @classmethod |
| def _make(cls, iterable, new=_tuple.__new__, len=len): |
| 'Make a new {typename} object from a sequence or iterable' |
| result = new(cls, iterable) |
| if len(result) != {num_fields:d}: |
| raise TypeError('Expected {num_fields:d}' |
| ' arguments, got %d' % len(result)) |
| return result |
| |
| def __repr__(self): |
| 'Return a nicely formatted representation string' |
| tmpl = self.__class__.__name__ + '({repr_fmt})' |
| return tmpl % self |
| |
| def _asdict(self): |
| 'Return a new OrderedDict which maps field names to their values' |
| return OrderedDict(zip(self._fields, self)) |
| |
| def _replace(_self, **kwds): |
| 'Return a new {typename} object replacing field(s) with new values' |
| result = _self._make(map(kwds.pop, {field_names!r}, _self)) |
| if kwds: |
| raise ValueError('Got unexpected field names: %r' % kwds.keys()) |
| return result |
| |
| def __getnewargs__(self): |
| 'Return self as a plain tuple. Used by copy and pickle.' |
| return tuple(self) |
| |
| __dict__ = _property(_asdict) |
| |
| def __getstate__(self): |
| 'Exclude the OrderedDict from pickling' # wat |
| pass |
| |
| {field_defs} |
| ''' |
|
|
| def namedtuple(typename, field_names, verbose=False, rename=False): |
| """Returns a new subclass of tuple with named fields. |
| |
| >>> Point = namedtuple('Point', ['x', 'y']) |
| >>> Point.__doc__ # docstring for the new class |
| 'Point(x, y)' |
| >>> p = Point(11, y=22) # instantiate with pos args or keywords |
| >>> p[0] + p[1] # indexable like a plain tuple |
| 33 |
| >>> x, y = p # unpack like a regular tuple |
| >>> x, y |
| (11, 22) |
| >>> p.x + p.y # fields also accessible by name |
| 33 |
| >>> d = p._asdict() # convert to a dictionary |
| >>> d['x'] |
| 11 |
| >>> Point(**d) # convert from a dictionary |
| Point(x=11, y=22) |
| >>> p._replace(x=100) # _replace() is like str.replace() but targets named fields |
| Point(x=100, y=22) |
| """ |
|
|
| |
| |
| if isinstance(field_names, str): |
| field_names = field_names.replace(',', ' ').split() |
| field_names = [str(x) for x in field_names] |
| if rename: |
| seen = set() |
| for index, name in enumerate(field_names): |
| if (not all(c.isalnum() or c == '_' for c in name) |
| or _iskeyword(name) |
| or not name |
| or name[0].isdigit() |
| or name.startswith('_') |
| or name in seen): |
| field_names[index] = '_%d' % index |
| seen.add(name) |
| for name in [typename] + field_names: |
| if not all(c.isalnum() or c == '_' for c in name): |
| raise ValueError('Type names and field names can only contain ' |
| 'alphanumeric characters and underscores: %r' |
| % name) |
| if _iskeyword(name): |
| raise ValueError('Type names and field names cannot be a ' |
| 'keyword: %r' % name) |
| if name[0].isdigit(): |
| raise ValueError('Type names and field names cannot start with ' |
| 'a number: %r' % name) |
| seen = set() |
| for name in field_names: |
| if name.startswith('_') and not rename: |
| raise ValueError('Field names cannot start with an underscore: ' |
| '%r' % name) |
| if name in seen: |
| raise ValueError('Encountered duplicate field name: %r' % name) |
| seen.add(name) |
|
|
| |
| fmt_kw = {'typename': typename} |
| fmt_kw['field_names'] = tuple(field_names) |
| fmt_kw['num_fields'] = len(field_names) |
| fmt_kw['arg_list'] = repr(tuple(field_names)).replace("'", "")[1:-1] |
| fmt_kw['repr_fmt'] = ', '.join(_repr_tmpl.format(name=name) |
| for name in field_names) |
| fmt_kw['field_defs'] = '\n'.join(_imm_field_tmpl.format(index=index, name=name) |
| for index, name in enumerate(field_names)) |
| class_definition = _namedtuple_tmpl.format(**fmt_kw) |
|
|
| if verbose: |
| print(class_definition) |
|
|
| |
| |
| namespace = dict(_itemgetter=_itemgetter, |
| __name__='namedtuple_%s' % typename, |
| OrderedDict=OrderedDict, |
| _property=property, |
| _tuple=tuple) |
| try: |
| exec(class_definition, namespace) |
| except SyntaxError as e: |
| raise SyntaxError(e.msg + ':\n' + class_definition) |
| result = namespace[typename] |
|
|
| |
| |
| |
| |
| try: |
| frame = _sys._getframe(1) |
| result.__module__ = frame.f_globals.get('__name__', '__main__') |
| except (AttributeError, ValueError): |
| pass |
|
|
| return result |
|
|
|
|
| |
| |
| |
|
|
| _namedlist_tmpl = '''\ |
| class {typename}(list): |
| '{typename}({arg_list})' |
| |
| __slots__ = () |
| |
| _fields = {field_names!r} |
| |
| def __new__(_cls, {arg_list}): # TODO: tweak sig to make more extensible |
| 'Create new instance of {typename}({arg_list})' |
| return _list.__new__(_cls, ({arg_list})) |
| |
| def __init__(self, {arg_list}): # tuple didn't need this but list does |
| return _list.__init__(self, ({arg_list})) |
| |
| @classmethod |
| def _make(cls, iterable, new=_list, len=len): |
| 'Make a new {typename} object from a sequence or iterable' |
| # why did this function exist? why not just star the |
| # iterable like below? |
| result = cls(*iterable) |
| if len(result) != {num_fields:d}: |
| raise TypeError('Expected {num_fields:d} arguments,' |
| ' got %d' % len(result)) |
| return result |
| |
| def __repr__(self): |
| 'Return a nicely formatted representation string' |
| tmpl = self.__class__.__name__ + '({repr_fmt})' |
| return tmpl % tuple(self) |
| |
| def _asdict(self): |
| 'Return a new OrderedDict which maps field names to their values' |
| return OrderedDict(zip(self._fields, self)) |
| |
| def _replace(_self, **kwds): |
| 'Return a new {typename} object replacing field(s) with new values' |
| result = _self._make(map(kwds.pop, {field_names!r}, _self)) |
| if kwds: |
| raise ValueError('Got unexpected field names: %r' % kwds.keys()) |
| return result |
| |
| def __getnewargs__(self): |
| 'Return self as a plain list. Used by copy and pickle.' |
| return tuple(self) |
| |
| __dict__ = _property(_asdict) |
| |
| def __getstate__(self): |
| 'Exclude the OrderedDict from pickling' # wat |
| pass |
| |
| {field_defs} |
| ''' |
|
|
|
|
| def namedlist(typename, field_names, verbose=False, rename=False): |
| """Returns a new subclass of list with named fields. |
| |
| >>> Point = namedlist('Point', ['x', 'y']) |
| >>> Point.__doc__ # docstring for the new class |
| 'Point(x, y)' |
| >>> p = Point(11, y=22) # instantiate with pos args or keywords |
| >>> p[0] + p[1] # indexable like a plain list |
| 33 |
| >>> x, y = p # unpack like a regular list |
| >>> x, y |
| (11, 22) |
| >>> p.x + p.y # fields also accessible by name |
| 33 |
| >>> d = p._asdict() # convert to a dictionary |
| >>> d['x'] |
| 11 |
| >>> Point(**d) # convert from a dictionary |
| Point(x=11, y=22) |
| >>> p._replace(x=100) # _replace() is like str.replace() but targets named fields |
| Point(x=100, y=22) |
| """ |
|
|
| |
| |
| if isinstance(field_names, str): |
| field_names = field_names.replace(',', ' ').split() |
| field_names = [str(x) for x in field_names] |
| if rename: |
| seen = set() |
| for index, name in enumerate(field_names): |
| if (not all(c.isalnum() or c == '_' for c in name) |
| or _iskeyword(name) |
| or not name |
| or name[0].isdigit() |
| or name.startswith('_') |
| or name in seen): |
| field_names[index] = '_%d' % index |
| seen.add(name) |
| for name in [typename] + field_names: |
| if not all(c.isalnum() or c == '_' for c in name): |
| raise ValueError('Type names and field names can only contain ' |
| 'alphanumeric characters and underscores: %r' |
| % name) |
| if _iskeyword(name): |
| raise ValueError('Type names and field names cannot be a ' |
| 'keyword: %r' % name) |
| if name[0].isdigit(): |
| raise ValueError('Type names and field names cannot start with ' |
| 'a number: %r' % name) |
| seen = set() |
| for name in field_names: |
| if name.startswith('_') and not rename: |
| raise ValueError('Field names cannot start with an underscore: ' |
| '%r' % name) |
| if name in seen: |
| raise ValueError('Encountered duplicate field name: %r' % name) |
| seen.add(name) |
|
|
| |
| fmt_kw = {'typename': typename} |
| fmt_kw['field_names'] = tuple(field_names) |
| fmt_kw['num_fields'] = len(field_names) |
| fmt_kw['arg_list'] = repr(tuple(field_names)).replace("'", "")[1:-1] |
| fmt_kw['repr_fmt'] = ', '.join(_repr_tmpl.format(name=name) |
| for name in field_names) |
| fmt_kw['field_defs'] = '\n'.join(_m_field_tmpl.format(index=index, name=name) |
| for index, name in enumerate(field_names)) |
| class_definition = _namedlist_tmpl.format(**fmt_kw) |
|
|
| if verbose: |
| print(class_definition) |
|
|
| def _itemsetter(key): |
| def _itemsetter(obj, value): |
| obj[key] = value |
| return _itemsetter |
|
|
| |
| |
| namespace = dict(_itemgetter=_itemgetter, |
| _itemsetter=_itemsetter, |
| __name__='namedlist_%s' % typename, |
| OrderedDict=OrderedDict, |
| _property=property, |
| _list=list) |
| try: |
| exec(class_definition, namespace) |
| except SyntaxError as e: |
| raise SyntaxError(e.msg + ':\n' + class_definition) |
| result = namespace[typename] |
|
|
| |
| |
| |
| |
| |
| try: |
| frame = _sys._getframe(1) |
| result.__module__ = frame.f_globals.get('__name__', '__main__') |
| except (AttributeError, ValueError): |
| pass |
|
|
| return result |
|
|