将嵌套列表与字典键进行比较并创建复合键值对

Question

I have a nested list and a dictionary and I want to compare list items with dictionary keys and if they match then the corresponding dictionary values should be added and appended to same dictionary new compound key-value pair as shown below:

colours = [['red', 'yellow'], ['green', 'black'], ['white', 'blue', 'orange'], ['pink', 'purple']]
dict1 = {'red': 10, 'black': 20, 'green': 30, 'neon':5, 'yellow': 40, 'orange':50, 'white':60, 
        'blue':70}

It should compare complete sublist item with dictionary keys and if present then dictionary values should be summed for those keys.

Expected result:

dict1 = {'red': 10, 'black': 20, 'green': 30, 'neon':5, 'yellow': 40, 'orange':50, 'white':60, 
        'blue':70, 'red + yellow':50, 'green + black':50, 'white + blue +orange':180}

The list is appended by some logic and the number of elements in sublists is not fixed.

With the help from fellow community member @tomjn I could do partially solve this problem and code is given below:

for i, j in itertools.combinations(itertools.chain(*colours), 2):
    if i in dict1 and j in dict1:
        dict1[f"{i} + {j}"] = dict1[i] + dict1[j]

Can anyone please help me complete this code?

Thanks in advance!

Answer 1

You don't need itertools for this, just an ordinary loop over colours .

for colorlist in colours:
    if (all(c in dict1 for c in colorlist)):
        dict1[" + ".join(colorlist)] = sum(dict1[c] for c in colorlist)