CODEWITHSUNDEEP
pythondictionary
Shubha Rajopadhye
Shubha Rajopadhye

Reputation: 49

Creating a dictionary in python by combining two .csv files

I am trying to create a dictionary in python by combining data from two .csv files, by matching the first column of the two files. This is what I have so far 

import csv

with open('a.csv', 'r') as my_file1 :
    rows1 = list(csv.reader(my_file1))
with open('aa.csv', 'r') as my_file2 :
    rows2 = list(csv.reader(my_file2))
max_length = min(len(rows1), len(rows2))

for i in range(10):
    new_dict = {}
    if (rows1[i][0]== rows2[i][0]):
        temp = {(rows1[i][0], (rows1[i][5], rows1[i][6],  rows2[i][5],  rows2[i][6] )) }
        new_dict.update(temp)
print(new_dict)

The output that I get is the last data entry in arrays. It does not seem to append all the values. This is what the output looks like 

{'2016-09-12': ('1835400', '45.75', '21681500', '9.78')}

instead of the complete list with keys and values. How do I go about correcting this? Thanks!

Upvotes: 1

Views: 306

Answers (1)

Moses Koledoye
Moses Koledoye

Reputation: 78564

You're creating a new dictionary on every iteration of your for, so only the update from the last iteration is kept, others have been thrown away.

You can solve this by moving the dictionary setup outside the for:

new_dict = {}
for i in range(10):
    ...

Upvotes: 1

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