Defaults for Fields

Provides optional default values with similar behaviour as function parameters. See docstring.

>>> Point = namedtuple('Point', ['x', 'y', 'z'], fielddefaults=(22, 33))
>>> Point.__doc__                   # docstring for the new class with defaults
'Point(x, y, z)\n    with optional default values fielddefaults=(22, 33)'
>>> Point(11)                       # instantiate with partial positional args or keywords
Point(x=11, y=22, z=33)
>>> Point(11, y=22)                 # instantiate with partial positional args or keywords
Point(x=11, y=22, z=33)
>>> p = Point(11, y=22)             # instantiate with positional args or keywords
>>> p[0] + p[1] + p[2]              # indexable like a plain tuple
66
>>> x, y, z = p                     # unpack like a regular tuple
>>> x, y, z
(11, 22, 33)
>>> p.x + p.y + p.z                 # fields also accessible by name
66
>>> d = p._asdict()                 # convert to a dictionary
>>> d['z']
33
>>> Point(**d)                      # convert from a dictionary
Point(x=11, y=22, z=33)
>>> p._replace(x=100)               # _replace() is like str.replace() but targets named fields
Point(x=100, y=22, z=33)
>>> p._replace(z=100)               # _replace() works for fields with default values as well
Point(x=11, y=22, z=100)