diff options
Diffstat (limited to 'Lib/collections.py')
| -rw-r--r-- | Lib/collections.py | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/Lib/collections.py b/Lib/collections.py index 90ed776..7b23948 100644 --- a/Lib/collections.py +++ b/Lib/collections.py @@ -30,7 +30,7 @@ def namedtuple(typename, field_names, verbose=False): 11 >>> Point(**d) # convert from a dictionary Point(x=11, y=22) - >>> p.__replace__('x', 100) # __replace__() is like str.replace() but targets a named field + >>> p.__replace__(x=100) # __replace__() is like str.replace() but targets named fields Point(x=100, y=22) """ @@ -60,7 +60,7 @@ def namedtuple(typename, field_names, verbose=False): template = '''class %(typename)s(tuple): '%(typename)s(%(argtxt)s)' __slots__ = () - __fields__ = %(field_names)r + __fields__ = property(lambda self: %(field_names)r) def __new__(cls, %(argtxt)s): return tuple.__new__(cls, (%(argtxt)s)) def __repr__(self): @@ -68,9 +68,9 @@ def namedtuple(typename, field_names, verbose=False): def __asdict__(self, dict=dict, zip=zip): 'Return a new dict mapping field names to their values' return dict(zip(%(field_names)r, self)) - def __replace__(self, field, value, dict=dict, zip=zip): - 'Return a new %(typename)s object replacing one field with a new value' - return %(typename)s(**dict(list(zip(%(field_names)r, self)) + [(field, value)])) \n''' % locals() + def __replace__(self, **kwds): + 'Return a new %(typename)s object replacing specified fields with new values' + return %(typename)s(**dict(zip(%(field_names)r, self) + kwds.items())) \n''' % locals() for i, name in enumerate(field_names): template += ' %s = property(itemgetter(%d))\n' % (name, i) if verbose: @@ -103,6 +103,10 @@ if __name__ == '__main__': p = Point(x=10, y=20) assert p == loads(dumps(p)) + # test and demonstrate ability to override methods + Point.__repr__ = lambda self: 'Point(%.3f, %.3f)' % self + print p + import doctest TestResults = namedtuple('TestResults', 'failed attempted') print(TestResults(*doctest.testmod())) |