CODEWITHSUNDEEP
pythonpython-3.x
Pjose123
Pjose123

Reputation: 15

Remove duplicated items in one list and add items with same index position in second list

I have two lists x and y and each item in x is pointing to corresponding position in y

x = [1,2,3,4,2,3]
y = [30, 40, 10, 80, 100,40]

I want to get as:

x=[1,2,3,4]  
y=[30,140,50,80]

Overall, remove duplicated items in x and add items in y with corresponding index positions

Upvotes: 1

Views: 76

Answers (4)

Ghost Ops
Ghost Ops

Reputation: 1734

Try this code

Just creates a new list of zeroes, whose length is based on the difference between length of list x and length of set of list x, and add the value of y to the value in the corresponding index (from the x list) into the res list

x = [1, 2, 3, 4, 2, 3]
y = [30, 40, 10, 80, 100,40]

res = [0]*len(set(x))

for i, j in enumerate(x):
    res[j-1] += y[i]

print(res)

Output:

[30, 140, 50, 80]

Tell me if its not working...

Upvotes: 0

iamakhilverma
iamakhilverma

Reputation: 596

Creating a dictionary to approach this problem will be easier-

d = dict()
for i in range(len(x)):
    if x[i] in d:
        d[x[i]] += y[i]
    else:
        d[x[i]] = y[i]

print(d)

Once you create the dictionary 'd' with desired result, you can create new x, y lists by obtaining the keys and values of that dictionary using list() command-

x, y = list(d) , list(d.values())

print(x)
print(y)

Upvotes: 0

azro
azro

Reputation: 54148

I'd suggest you create a dict where the key is the value from x and the value is sum of values from y using index from x

Then zip to passe from pairs [(1, 30), (2, 140), (3, 50), (4, 80)] back to x,y lists

x = [1, 2, 3, 4, 2, 3]
y = [30, 40, 10, 80, 100, 40]

results = defaultdict(int)
for i, vx in enumerate(x):
    results[vx] += y[i]
print(results)  # {1: 30, 2: 140, 3: 50, 4: 80}

new_x, new_y = zip(*results.items())
print(new_x)  # (1, 2, 3, 4)
print(new_y)  # (30, 140, 50, 80)

Upvotes: 2

nikeros
nikeros

Reputation: 3379

A super basic approach could be using a good old loop:

res = {}
for i1, i2 in zip(x, y):
    res[i1] = res.get(i1, 0) + i2 # if i1 not in res, will default to 0

x = list(res.keys())
y = [res[i] for i in x]

Upvotes: 0

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