List of tuples, remove the ones with same 1st item but make the remaining copy's 3rd item the sum of both 3rd items

user_7106164 0
Viewed 23

Title got confusing so heres an example. I have this list of tuples:

results = [(3941, 'Athens El. Venizelos', 2), (1472, 'Rhodes Diagoras', 1), (3941, 'Athens El. Venizelos', 11)]

I need to change it in order for it to become :

results = [(3941, 'Athens El. Venizelos', 13), (1472, 'Rhodes Diagoras', 1)]

Obviously the code needs to work for big lists with many duplicates, heres what I have so far:

    i = 0
    j = 0
    while i<len(results):
        temp1 = results[i]
        while j<len(results):
            temp2 = results[j]
            if temp1[0] == temp2[0] and i!=j:
                temp1 = list(temp1)
                temp1[2] = temp1[2]+temp2[2]
                temp1 = tuple(temp1)
                del results[j]
            j+=1
        i+=1       
    print(results)

My issue is that the outer while only completes once and I have no clue why. Any help appreciated. Note: This is my first day of writing python so if the code is abysmally wrong I'm sorry in advance.

duplicates tuples list python
2 Answers

Try:

results = [
    (3941, "Athens El. Venizelos", 2),
    (1472, "Rhodes Diagoras", 1),
    (3941, "Athens El. Venizelos", 11),
]

tmp = {}
for a, b, c in results:
    tmp[a] = a, b, c + tmp.get(a, (None, None, 0))[2]

print(list(tmp.values()))

Prints:

[(3941, 'Athens El. Venizelos', 13), (1472, 'Rhodes Diagoras', 1)]
user_100359850

In terms of the bug fixes that are required to the original algorithm:

i = 0
while i<len(results):
    temp1 = results[i]
    j = 0                     # <=== this needs to be inside the outer loop
    while j<len(results):
        temp2 = results[j]
        if temp1[0] == temp2[0] and i!=j:
            temp1 = list(temp1)
            temp1[2] = temp1[2]+temp2[2]
            results[i] = tuple(temp1)    # <=== need to assign back into results[i]
            del results[j]
        j+=1
    i+=1       
print(results)
user_135960370
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