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I have 2 tuples which I need to combine into a dictionary. tuple 2 ( the values ) is exactly half the length of tuple 1 ( the keys )

validexts = ( 
'.pz3','.cr2','.pz2','.pp2','.hr2','.fc2','.hd2','.lt2','.cm2','.mt5','.mc6',
'.pzz','.crz','.p2z','.ppz','.hrz','.fcz','.hdz','.ltz','.cmz','.mz5','.mcz' )

validvalues = ( 
    'scene','character','pose','props','hair','face','hand','light',
    'camera','materials','materials )

how can I make a dictionary ( the values will be repeated for the second part of the key list ) from these 2 tuples in python ?

so far my solution has been to double the values like this

validvalues += validvalues
validdict = dict( zip( validexts, validvalues ) )

I would like to know if there is a more pythonic way.

structure
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2 Answers2

3

The canonical way here would be itertools.cycle:

from itertools import cycle
dict(zip(validexts, cycle(validvalues)))

Output:

{'.pz3': 'scene',
 '.cr2': 'character',
 '.pz2': 'pose',
 '.pp2': 'props',
 '.hr2': 'hair',
 '.fc2': 'face',
 '.hd2': 'hand',
 '.lt2': 'light',
 '.cm2': 'camera',
 '.mt5': 'materials',
 '.mc6': 'materials',
 '.pzz': 'scene',
 '.crz': 'character',
 '.p2z': 'pose',
 '.ppz': 'props',
 '.hrz': 'hair',
 '.fcz': 'face',
 '.hdz': 'hand',
 '.ltz': 'light',
 '.cmz': 'camera',
 '.mz5': 'materials',
 '.mcz': 'materials'}

As mentioned in the documentation, cycle repeats the iterable indefinitely:

Make an iterator returning elements from the iterable and saving a copy of each. When the iterable is exhausted, return elements from the saved copy. Repeats indefinitely.

U13-Forward
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0

You can go with

from itertools import chain
validdict = dict( zip( validexts, chain(validvalues, validvalues) ) )

This will not copy the validvalues tuple.

Yu Cheng
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