Comparing Csv Matching Rows With Python

I have two CSVs containing only one column, each: littleListIPs.csv: 10.187.172.140 10.187.172.141 10.187.172.142 10.187.172.143 10.187.172.144 10.187.172.145 10.187.172.154 10.18

Solution 1:

Written in python 2.x, since that's what I have handy.

• Load BigIp list into a set. Checking for in an array is O(n), checking for in a set is O(1).
• use with to open the files, which is good practice and makes sure they were closed properly.

code:

#!/usr/bin/env pythonimport csv

little_ip_filename = "littleListIPs.csv"
big_ip_filename = "BigListIPs.csv"
output_filename = "results.csv"# Load all the entries from BigListIPs into a set for quick lookup.
big_ips = set()

withopen(big_ip_filename, 'r') as f:
    big_ip = csv.reader(f)
    for csv_row in big_ip:
        big_ips.add(csv_row[0])

# print big_ipswithopen(little_ip_filename, 'r') as input_file, open(output_filename, 'w') as output_file:
    input_csv = csv.reader(input_file)
    output_csv = csv.writer(output_file)
    for csv_row in input_csv:
        ip = csv_row[0]
        status = "Present"if ip in big_ips else"Not Present"
        output_csv.writerow([ip, status + " in BigListIPs.csv"])

littleListIPs.csv:

10.187.172.140
10.187.172.141
10.187.172.142
10.187.172.143
10.187.172.144
10.187.172.145
10.187.172.154
10.187.172.155

BigListIPs.csv:

10.187.172.146
10.187.172.147
10.187.172.148
10.187.172.149
10.187.172.150
10.187.172.151
10.187.172.152
10.187.172.153
10.187.172.154
10.187.172.155

results.csv:

10.187.172.140,Not Present in BigListIPs.csv
10.187.172.141,Not Present in BigListIPs.csv
10.187.172.142,Not Present in BigListIPs.csv
10.187.172.143,Not Present in BigListIPs.csv
10.187.172.144,Not Present in BigListIPs.csv
10.187.172.145,Not Present in BigListIPs.csv
10.187.172.154,Present in BigListIPs.csv
10.187.172.155,Present in BigListIPs.csv

Solution 2:

You can just use in to check if IP is in BigList and then write to third file

littlelistIPs = ['10.187.172.140', '10.187.172.141', '10.187.172.142', '10.187.172.143',
                '10.187.172.144', '10.187.172.145', '10.187.172.154', '10.187.172.155']

biglistIPs = ['10.187.172.146', '10.187.172.147', '10.187.172.148', '10.187.172.149',
              '10.187.172.150', '10.187.172.151', '10.187.172.152', '10.187.172.153',
              '10.187.172.154', '10.187.172.155']

with open('output.csv', 'w') as f:
    for i in littlelistIPs:
        if i in biglistIPs:
            f.write(i + ' | present in BigListIPs.csv\n')
        else:
            f.write(i + ' | Not present in BigListIPs.csv\n')