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I am trying to create a dictionary through a comprehension but I have to use keys from a specific range of numbers and values from a predefined list:

pssmList=[]
for column in columns:
    pssmList.append(collections.Counter(column))

pssmDict = {key:value for key in range(0, len(pssmList)) for value in 
pssmList}

Now, I know that the Counter object is a type of dict but I need those objects inside of pssmDict assigned to keys from a numerical range specified above and all I get is the last element in pssmList repeated over and over again, although each line should be different (and yes, I checked the list and it really contains different records):

 Key   Number         
0     Counter({'T': 8, 'E': 4, 'P': 2, 'V': 1, 'S': 1, 'D': 1})
1     Counter({'T': 8, 'E': 4, 'P': 2, 'V': 1, 'S': 1, 'D': 1})
2     Counter({'T': 8, 'E': 4, 'P': 2, 'V': 1, 'S': 1, 'D': 1})
3     Counter({'T': 8, 'E': 4, 'P': 2, 'V': 1, 'S': 1, 'D': 1})
4     Counter({'T': 8, 'E': 4, 'P': 2, 'V': 1, 'S': 1, 'D': 1})
5     Counter({'T': 8, 'E': 4, 'P': 2, 'V': 1, 'S': 1, 'D': 1})

Desired output:

 Key   Number         
0     Counter({'V': 14, 'L': 2, 'A': 1})
1     Counter({'D': 17}) 
2     Counter({'F': 17})
3     Counter({'S': 8, 'W': 5, 'Y': 3, 'T': 1})
4     Counter({'A': 17})
5     Counter({'T': 8, 'E': 4, 'P': 2, 'V': 1, 'S': 1, 'D': 1})

Does anyone have any idea why this does not work? I've searched StackOverflow for similar problems but either I'm bad at searching or such questions haven't appeared.

Please excuse me if my mistake is trivial, I'm in my third month of learning Python (and coding altogether).

Krzysztof Czarnecki
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  • I updated the question with a representation of the desired output. I use string formatting to get table view, I just figured I'd show the part of code that doesn't really work – Krzysztof Czarnecki Mar 15 '18 at 23:21

1 Answers1

3

Zip the two sources together:

pssmDict = {key: value for key, value in zip(range(0, len(pssmList)), pssmList)}

However, in this case, you can simply use enumerate to generate the keys.

pssmDict = {key: value for key, value in enumerate(pssmList)}

The results of zip and enumerate are suitable for passing directly to dict; no need for a dictionary comprehension:

pssmDict = dict(enumerate(pssmList))
chepner
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