bob said unto the world upon 11/01/06 10:47 PM:
> At 08:31 PM 1/11/2006, Steve Haley wrote:
>
>>Hello everyone,
>>
>>I need to do something very simple but I'm having trouble finding
>>the way to do it - at least easily. I have created a tuple and now
>>need to find the position of individual members of that
>>tuple. Specifically, the tuple is something like: words = ("you",
>>"me", "us", "we", "and", "so", "forth") and I need to be able to
>>name a member, for example, "us" and find what the position (index)
>>of that word is in the tuple.
>>
>>I would have thought there would be a simple built in function for
>>that but I just went through the built in functions in the Python
>>Library Reference and I didn't find anything. I could probably
>>figure out how to write a while loop or something to do a sequential
>>search until I found the right member but I really believe there
>>must be an easier way and I'm just not seeing it. You can probably
>>tell I'm just learning Python so any help would be appreciated.
>
>
> Unfortunately there is no list method find. Sigh. Here's how I'd do it:
>
> # create a dictionary with each word as key and ordinal as value
> words = dict([(n,m) for m,n in enumerate(("you", "me", "us", "we",
> "and", "so", "forth"))])
> words["me"] # returns 1
>
I assume Bob meant that tuples have no index or find method. His
suggested procedure will work, but it seems more work than:
>>> t = ("I'm", "a", "tuple.", "I", "have", "only", "magic", "methods.")
>>> l = list(t)
>>> l.index("have")
4
>>> t[4]
'have'
>>>
I say more work as the way above builds a list to turn into a
dictionary. But, since dictionary access is fast, it might be quicker
for long tuples where the sought item is near then end. If it matters,
test.
HTH,
Brian vdB
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