方法/步骤 1 python 3的命名元组在collections模块内，如图。构造命名元组非常简单，使用namedtuple然后指定类型名和各个字段名。2 各个字段名除了可以写成一个字符串，空格隔开，也可以写成一个列表，如图。要读取字段值，使用'.'运算符。3 此外，命名元组还可以通过数字下标读取各个字段，也可以多赋值来展开...
>>> # Basic example >>> Point = namedtuple('Point', ['x', 'y']) >>> p = Point(11, y=22) # instantiate with positional or keyword arguments >>> p[0] + p[1] # indexable like the plain tuple (11, 22) 33 >>> x, y = p # unpack like a regular tuple >>> x, y (...
field_names)) num_fields = len(field_names) arg_list = repr(field_names).replace("'", "")[1:-1] repr_fmt = '(' + ', '.join(f'{name}=%r' for name in field_names) + ')' tuple_new = tuple.__new__ _dict, _tuple, _len, _map, _zip = dict, tuple, len, map...
the __module__ variable needs to be set to the frame#where the named tuple is created. Bypass this step in environments where#sys._getframe is not defined (Jython for example) or sys._getframe is not#defined for arguments greater than 0 (IronPython), or where the user has#specified a...
... # For pickling to work, the __module__ variable needs to be set to the frame # where the named tuple is created. Bypass this step in environments where # sys._getframe is not defined (Jython for example) or sys._getframe is not # defined for arguments greater than 0 (IronPyth...
_len=len# Create all the named tuple methods to be added to the class namespace# 'def __new__(_cls, name, shares, price, date, time): return _tuple_new(_cls, (name, shares, price, date, time))'s=f'def __new__(_cls,{arg_list}): return _tuple_new(_cls, ({arg_list})...
_source) # For pickling to work, the __module__ variable needs to be set to the frame # where the named tuple is created. Bypass this step in environments where # sys._getframe is not defined (Jython for example) or sys._getframe is not # defined for arguments greater than 0 (...
python2.6新特性named tuple named tuple Any tuple subclass whose indexable elements are also accessible using named attributes (for example, time.localtime() returns a tuple-like object where the year is accessible either with an index such as t[0] or with a named attribute like t.tm_year)....
In Python, it’s okay to leave a comma after the last item of a list, tuple, or dictionary. Also, you don’t need to indent, as I did in the preceding example, when you’re typing keys and values within thecurly braces. It just helps readability. ...
Up to this point, you’ve learned a lot about Python tuples. You now know that they’re immutable sequences that can contain heterogeneous data. Even though tuples have a few cool features, their functionality is pretty limited. For example, you can only access tuple items using numeric in...