Question

So I have a python dict like:

 1:[ "red","blue","green"]
 2: ["blue","blue","red"]..

and so on.

and then i have another python dict:
score_dict = {

 pid: weight
 1: 2
 2: 20
 ...
}

So, what i want is..
in the first dict, count number of times two colors occur together.
and so on.
But that count be multiplied by their weight.

For example:

I want to find out how many times red an blue occured together in this list:

so for pid 1
red and blue occurs once.

 so this is (1*2) # 2 comes from the score_dict as pid1 has a weight 2

and then for second

there are two blue, red pairs I can form

so this is (1*20) + (1*20)

So total score for blue and red occuring together is 2 + 20 + 20 = 42

Also, how do i extend it to 3 colors?

Like if i have to find out “red” “blue” and ” green” occuring together?

Answer 1

from collections import Counter

dict1 = {1:[ "red","blue","green"], 2: ["blue","blue","red"]}

weight = {1: 2, 2: 20}

score = 0

for k,v in dict1.iteritems():
    score += weight[k] * Counter(v)["red"] * Counter(v)["blue"]

Result:

>>> score
42

The last part of my code could be rewritten as generator comprehension:

score = sum(weight[k] * Counter(v)["red"] * Counter(v)["blue"] for k,v in dict1.iteritems())