invert dictionary with list &c
Des Small
des.small at bristol.ac.uk
Wed Nov 26 12:06:53 EST 2003
Lately I have found myself using a pattern to make new dictionaries
quite often, by which I mean twice:
def invert(d):
nd = {}
[nd.setdefault(val, []).append(key) for k, v in d]
return nd
def count(l):
d = {}
[d.setdefault(w, 0) += 1 for w in l]
return d
Is this the pythonic way to do such things? Ideally I'd like to write
them as one liners, but I can't see how.
Des
--
"[T]he structural trend in linguistics which took root with the
International Congresses of the twenties and early thirties [...] had
close and effective connections with phenomenology in its Husserlian
and Hegelian versions." -- Roman Jakobson
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