How two merge several .csv files horizontally with python?

Question

I\'ve several .csv files (~10) and need to merge them together into a single file horizontally. Each file has the same number of rows (~300) and 4 header lines which are not

Answer 1

You dont need to use csv module for this. You can just use

file1 = open(file1)

After opening all your files you can do this

from itertools import izip_longest

foo=[]
for new_line in izip_longest(file1,fil2,file3....,fillvalue=''):
    foo.append(new_line)

This will give you this structure (which kon has already told you)..It will also work if you have different number of lines in each file

[ ("line10", "line20", "line30", "line40"),
  ("line11", "line21", "line31", "line41"),
  ... 
]

After this you can just write it to a new file taking 1 list at a time

for listx in foo:
    new_file.write(','.join(j for j in listx))

PS: more about izip_longest here