Chris Rebert wrote:
On Wed, Aug 12, 2009 at 4:34 PM, jschwab<jsch...@gmail.com> wrote:
<snip>
As a more concrete example, say I have several sets of letters in a
list of strings
letters = ["aeiou", "hnopty", "egs", "amsp"]
and I wanted to build a regular expression string out of them like
re_str <==> "[aeiou][hnopty][egs][amsp]"
Right now, the best I've got that doesn't require an explicit string
like "[{1}][{2}][{3}][{4}]" is
re_str = "".join(map(lambda x: "[{0}]".format(x), letters))
Is there a better way?
Slightly better, by using a generator expression instead of map() and lambda:
re_str = "".join("[{0}]".format(x) for x in letters)
Though obviously MRAB's is shorter (and a good show of lateral thinking).
Python 3.1 supports auto-numbered placeholders "[{}]", so:
re_str = ("[{}]" * len(letters)).format(*letters)
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