Do you guys see any merit in changing the argument order for ifilter so
that the predicate function can just be an optional argument:
ifilter(data[, pred])
Alex Martelli successfully lobbied for groupby() to have that same
argument order. Originally, the signature was groupby(key, iterable)
but it worked-out much better to have groupby(iterable[, key]).
Also, I like swapped arguments because it more closely parallels the
order used in an equivalent list comprehension:
[e for e in iterable if pred(e)]