[Python-Dev] syntactic support for sets (original) (raw)

Raymond Hettinger raymond.hettinger at verizon.net
Wed Feb 1 20:50:28 CET 2006

[Greg Wilson]

I have a student who may be interested in adding syntactic support for sets to Python, so that:

x = {1, 2, 3, 4, 5} and: y = {z for z in x if (z % 2)} would be legal. There are of course issues (what's the syntax for a frozen set? for the empty set?), but before he even starts, I'd like to know if this would ever be considered for inclusion into the language.

Generator expressions make syntactic support irrelevant:

x = set(xrange(1,6)) y = set(z for z in x if (z % 2)) y = frozenset(z for z in x if (z % 2))

Accordingly,Guido rejected the braced notation for set comprehensions.
See: http://www.python.org/peps/pep-0218.html

Raymond

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