collections.namedtuple(typename, field_names, verbose=False, rename=False) 返回一个新类型名称typenname的元组。參数field_names是一个字串表示的元素名称,每一个字段之间能够通过空格、逗号方式来分隔,比方’x y’,’x, y’。 另外也能够採用列表的方式,比方[‘x’, ‘y’]。在字段名称命名上须要注意的是...
field_names=tuple(field_names),num_fields=len(field_names),arg_list=repr(tuple(field_names)).replace("'","")[1:-1],repr_fmt=', '.join(_repr_template.format(name=name)fornameinfield_names),field_defs='\n'.join(_field_template.format(index=index,name=name)forindex,nameinenumerate(fie...
collections.namedtuple(typename, field_names, verbose=False, rename=False) 返回一个新类型名称typenname的元组。參数field_names是一个字串表示的元素名称,每一个字段之间能够通过空格、逗号方式来分隔,比方’x y’,’x, y’。 另外也能够採用列表的方式,比方[‘x’, ‘y’]。在字段名称命名上须要注意的是...
# passenger.py from collections import namedtuple from database import get_column_names Passenger = namedtuple("Passenger", get_column_names()) 但是,当您运行代码时,您会得到如下所示的异常回溯: Traceback (most recent call last): ... ValueError: Type names and field names cannot be a keyword:...
__class__.__name__ + '({repr_fmt})' % self def _asdict(self): 'Return a new OrderedDict which maps field names to their values.' return OrderedDict(zip(self._fields, self)) def __getnewargs__(self): 'Return self as a plain tuple. Used by copy and pickle.' return tuple(...
(_self, **kwds):'Return a new Point object replacing specified fields with new values'result = _self._make(map(kwds.pop, ('x','y'), _self))ifkwds:raiseValueError('Got unexpected field names: %r'% kwds.keys())returnresultdef__getnewargs__(self):'Return self as a plain tuple. ...
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): ...
Namedtuple,顾名思义就是为了方便使得tuple每一项都有实际的意义,如果你想建立一个简单的不想改变的且没有method的类(尤其是数据库读出来的数据),那么使用namedtuple就会特别方便。 创建就用collections.namedtuple(typename, field_names, *, rename=False, defaults=None, module=None),一个返回class的工厂方法。
(self): 'Return a new dict which maps field names to their values.' return _dict(_zip(self._fields, self)) def __getnewargs__(self): 'Return self as a plain tuple. Used by copy and pickle.' return _tuple(self) # Modify function metadata to help with introspection and debugging ...
>>>fromcollectionsimportnamedtuple>>>Point=namedtuple("Point",["x","_y"])Traceback(most recent call last):...ValueError:Field names cannot startwithan underscore:'_y' 在此示例中,第二个字段名称以和下划线开头,因此您会收到ValueError通知,字段名称不能以该字符开头。这是为了避免与namedtuple方法和属...