How to sort a text file based on column in Python?

Question

I have a file(file.txt) containing the following data:

192.168.10.1/16, 22, 3265, tcp
172.144.32,2/34, 22, 21, udp
10.128.16.234/8, 0, 20, icmp

I need to sort this by cloumn[0], cloumn[1] and column[2]

Answer 1

My solution is to create a list of tuples (one tuple for each line)like this:

(data_in_column_of_interest, entire_line)

Where the data_in_column_of_interest is any datatype and entire_line is string.

then just sort this list:

def sortLinesByColumn(readable, column, columnt_type):
    """Returns a list of strings (lines in readable file) in sorted order (based on column)"""
    lines = []

    for line in readable:
        # get the element in column based on which the lines are to be sorted
        column_element= columnt_type(line.split(',')[column-1])
        lines.append((column_element, line))

    lines.sort()

    return [x[1] for x in lines]


with open('G:/Ftest/data.txt') as f:
    # sort the lines based on column 1, and column 1 is type int
    sorted_lines = sortLinesByColumn(f, 1, int)

    for l in sorted_lines:
        print(l)

Input: File containing:

1, Bob, 123
5, Mary, 112
0, Allen, 2421
1, lucy, 341

output: a list of strings:

0, Allen, 2421
1, Bob, 123
1, lucy, 341
5, Mary, 112