Compare A Column Between 2 Csv Files And Write Differences Using Python

I am trying to print out the differences by comparing a column between 2 csv files. CSV1: SERVER, FQDN, IP_ADDRESS, serverA, device1.com, 10.10.10.1 serverA,device2.com,10

Solution 1:

This code uses the built-in difflib to spit out the lines from file1.csv that don't appear in file2.csv and vice versa.

I use the Differ object for identifying line changes. I assumed that you would not regard line swapping as a difference, that's why I added the sorted() function call.

from difflib import Differ
csv_file1 = sorted(open("file1.csv", 'r').readlines())
csv_file2 = sorted(open("file2.csv", 'r').readlines())
with open("diff.csv", 'w') as f:
    for line in Differ().compare(csv_file1,csv_file2)):
        dmode, line = line[:2], line[2:]
        if dmode.strip() == "":
            continue
        f.write(line + "\n")

Note that if the line differs somehow (not only in the FQDN column) it would appear in diff.csv

Solution 2:

import csv

data = {}  # creating list to store the data

with open('CSV1.csv', 'r') as lookuplist, open('CSV2.csv', 'r') as csvinput, open('Output.csv', 'w') as f_output:
 reader1 = csv.reader(lookuplist)
 reader2 = csv.reader(csvinput)
 csv_output = csv.writer(f_output)
 fieldnames = (['FQDN', 'IP_ADDRESS', 'SERVER', 'LOCATION'])
 csv_output.writerow(fieldnames)  # prints header to the output file
 _tempFqdn = []
 for i,dt in enumerate(reader1):
     if i==0:
         continue
     _tempFqdn.append(dt[1].strip())
 for i,col in enumerate(reader2):
     if i==0:
         continue
     if col[0].strip() not in _tempFqdn:
         csv_output.writerow(col)

Solution 3:

import csv

data = {}  # creating dictionary to store the data

with open('CSV1.csv', 'r') as lookuplist:
reader1 = csv.reader(lookuplist)
for col in reader1:
    data[col[1]] = col[1]  # stores the data from column 0 to column 1 in the data list

with open('CSV2.csv', 'r') as csvinput, open('Output.csv', 'w', newline='') as f_output:
reader2 = csv.reader(csvinput)
csv_output = csv.writer(f_output)
fieldnames = (['SERVER', 'FQDN', 'AUTOMATION_ADMINISTRATOR', 'IP_ADDRESS', 'PRIMARY_1', 'MHT_1', 'MHT_2',
               'MHT_3'])
csv_output.writerow(fieldnames)  # prints header to the output file

for col in reader2:
    if col[0] not in data:  # if the column 1 in CSV1 does not match with column 0 in CSV2 Extract
    col = [col[0]]


        csv_output.writerow(col)  # writes all the data that is matched in CMDB WLC Extract

So basically, I only had to change 'not in' under 'for loop' and change the columns in the data list that will be reading from the CSV1 file that I am creating.