Merge Multiple Csv's Using Python

I am new to python and I have got to a point where I have created multiple csv file from large text files. So my csv's look like below. CSV1 ABC, 1 DEF, 2 GHI, 3 CSV2 ABC, 4 DEF,

Solution 1:

import csv
from collections import defaultdict

csvs = ["data1.csv", "data2.csv"]
for file in csvs:
    for line in csv.reader(open(file)):
        d.setdefault(line[0], []).append(line[1]) 

with open("result.csv", "w") as f:
    wrt = csv.writer(f)
    wrt.writerows([[k] + v for k, v in d.items()])

Solution 2:

Assuming all the CSV files are of the same length and contain the same first column in the same order, something like this might work for you:

list_of_files = ['csv1.csv', 'csv2.csv', 'csv3.csv']

# Use the first file as a template
with open(list_of_files[0], 'r') as f:
    output_text = [line.strip() for line in f]

# Append the values to the end of the lines
for fn in list_of_files[1:]:
    with open(fn, 'r') as f:
        for i, line in enumerate(f):
            key, value = line.strip().split(",")
            output_text[i] += "," + value

# Dump result to new csv
with open("result.csv", 'w') as f:
    f.write("\n".join(output_text))