Slicing a List Converting a Nested List into a Dictionary ( Pairing a List of Values to the key)-CodePudding

I previously asked a question here, about how to slice strings and using them as keys and values, and people helped me to come up with a solution which is below:

from collections import defaultdict

lst = [
    'Macbook Air - 13inch Model',
    'Iphone13 - Max Pro 65GB Model',
    'Airpod2'
    ]
dc = defaultdict(str)

for item in lst:
    x, *y = item.split('-')
    dc[x] = y
    
print(dc)

Output:

defaultdict(<class 'str'>, {'Macbook Air ': [' 13inch Model'], 'Iphone13 ': [' Max Pro 65GB Model'], 'Airpod2': []})

however, what if it ends up generating the same key and I wanted to have a list of values paired within the same key name?

for example:

lst = [
    'Macbook Air - 13inch Model',
    'Iphone13 - Max Pro 65GB Model',
    'Iphone13 - Max 128GB Model',
    'Airpod2'
    ]

and output will be looking like:

defaultdict(<class 'str'>, {'Macbook Air ': [' 13inch Model'], 'Iphone13 ': [' Max Pro 65GB Model', 'Pro 128GB Model'], 'Airpod2': []})

I assumed it will automatically stored more than one values but it only paired with the first key and value and others with the same key name disappeared.

CodePudding user response：

Make it a defaultdict of lists rather than strings:

from collections import defaultdict

lst = [
    'Macbook Air - 13inch Model',
    'Iphone13 - Max Pro 65GB Model',
    'Iphone13 - Max 128GB Model',
    'Airpod2'
    ]
dc = defaultdict(list)

for item in lst:
    x, *y = item.split('-')
    dc[x].extend(y)

gives you a dc with the following contents:

defaultdict(<class 'list'>, {
    'Macbook Air ': [' 13inch Model'],
    'Iphone13 ': [' Max Pro 65GB Model', ' Max 128GB Model'],
    'Airpod2': []
})