I've written a decorator to go along with Guido's proposed
implementation, to make it easier to write item dunders that
take positional args that can also be specified by keyword.
#-----------------------------------------------
from inspect import signature
def positional_indexing(m):
def f(self, args, **kwds):
if isinstance(args, tuple) and len(args) != 1:
return m(self, *args, **kwds)
else:
return m(self, args, **kwds)
f.__name__ = m.__name__
f.__signature__ = signature(m)
return f
#-----------------------------------------------
Usage example:
#-----------------------------------------------
class Test:
def __init__(self):
self.data = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
@positional_indexing
def __getitem__(self, i, j):
return self.data[i][j]
t = Test()
print(signature(t.__getitem__))
print(t[1, 2])
# Have to fake this for now until we get real keyword index syntax
print(t.__getitem__((), j = 2, i = 1))
#-----------------------------------------------
Output:
(i, j)
6
6
--
Greg
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