How can I transform csv data in python

Question

I have a csv file that I want to transform. Currently the data looks like this in the csv file

115776 1142 1523 20197 20394 3421 1284 9572 19682

but I want it to look like this

115776 1142
115776 1523
115776 20197
115776 20394
115776 3421

.....

any idea on how to achieve this?

I currently wrote a function to get it and it gets it like this

for row in read_csv(testfile, "Recipes_RecipeId Recipes_Ingredients_0_IngredientID Recipes_Ingredients_1_IngredientID Recipes_Ingredients_2_IngredientID Recipes_Ingredients_3_IngredientID Recipes_Ingredients_4_IngredientID Recipes_Ingredients_5_IngredientID Recipes_Ingredients_6_IngredientID Recipes_Ingredients_7_IngredientID Recipes_Ingredients_8_IngredientID".split()):
    with open('recipeIngredientID.csv', 'a') as csvfile:
        spamwriter = csv.writer(csvfile, delimiter=' ',
                            quotechar='|', quoting=csv.QUOTE_MINIMAL)
        spamwriter.writerow(row)

is there any better way to do it where it prints it out I want it?

Besides, what have you tried, whats the delimiting, is that all in one row in separate columns or in one cell? If you want help, help us help you. — gold_cy, Apr 04 '17 at 18:46

score 0 · Accepted Answer · edited May 23 '17 at 12:18

0

Read the csv into a python list: Python import csv to list

And then simply loop over the list with repeating the first index:

test = [115776, 1142, 1523, 20197, 20394, 3421, 1284, 9572, 19682]

for i in test[1:]:
     print test[0], i

edited May 23 '17 at 12:18

Community

1
1

answered Apr 04 '17 at 18:47

bjpreisler

118
1
8

The very first output of this is not what OP wants. – gold_cy Apr 04 '17 at 18:49

score 0 · Answer 2 · answered Aug 25 '22 at 13:12

For smaller csv you can load csv to array of arrays, make empty rotated array and copy data. Like this...

head -n 10 vf.txt | python -c "
import sys
import csv
reader=csv.reader(sys.stdin)
mx = []
for row in reader:
    mx.append(row)

cols = len(mx[0])
rows = len(mx)
outp = [[None for e in range(0,rows) ] for i in range(0,cols)]
for r in range(0, rows):
    for c in range(0,cols):
        outp[c][r] = mx [r][c]

writer = csv.writer(sys.stdout)
for r in outp:
    writer.writerow(r)
"""

How can I transform csv data in python

2 Answers2