[Tutor] python equivalent to perl hash slices?

[Bill Campbell]

On Tue, Aug 03, 2004, Danny Yoo wrote:
>
>> That being said, your particular code example can be written with zip(),
>> since you have a list of keys and values, and you want to just put them
>> together.  Here's an example of zip():
>>
>> ###
>> >>> zip(["zero", "one", "two", "three", "four", "five"],
>> ...     [0, 1, 2, 3, 4, 5])
>> [('zero', 0), ('one', 1), ('two', 2), ('three', 3), ('four', 4), ('five',
>> 5)]
>> ###
>
>Hi Bill,
>
>Gah!  That's wrong!  *grin*

A mistake!  I've never made one of those (a few million maybe :-).

>I'm sorry; I must have been daydreaming.  The above produces a list of
>key-value pairs, but that's not a dict.  So needs one more thing:
>dict():
>
>###
>>>> cols = ['zero', 'one', 'two', 'three', 'four', 'five']
>>>> vals = [0, 1, 2, 3, 4, 5]
>>>> d = dict(zip(cols, vals))
>>>> d
>{'three': 3, 'two': 2, 'four': 4, 'zero': 0, 'five': 5, 'one': 1}
>###
>
>And now we have a dictionary.

I remember now reading about zip in the O'Reilly ``Learning
Python'' book, and thinking it might be useful.

One could then get the array slice for values with something like this, or
is there an easier way?

>>> map((lambda k: d.get(k, None)), cols)

Bill
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