how to enhance my dataset output using python

Question

I have 2 input files, input.txt and datainput.txt . I check if the 2nd column of input.txt matches the 1st column of datainput.txt , and if they match, then I put it's orthodb_id at the end relevant row in the output file.

input.txt:

5 21 218
6 11 1931
7 26 173

datainput.txt:

>21|95|28|5
Computer
>11|28|5|5
Cate 

code.py:

import csv

with open('input.txt', 'rb') as file1:
    file1_data = dict(line.split(None, 2)[1::-1] for line in file1 if line.strip())

with open('data.txt', 'rb') as file2, open('output.txt', 'wb') as outputfile:
    output = csv.writer(outputfile, delimiter='|')
    for line in file2:
        if line[:1] == '>':
            row = line.strip().split('|')
            key = row[0][1:]
            if key in file1_data:
                 output.writerow(row + [file1_data[key]])

This is the output I get with my code:

>21|95|28|5|5
>11|28|5|5|6

Answer 1

You need just add an else block in your code to get the desired output:

import csv

with open('input.txt', 'rb') as file1:
    file1_data = dict(line.split(None, 2)[1::-1] for line in file1 if line.strip())

with open('data.txt', 'rb') as file2, open('output.txt', 'wb') as outputfile:
    output = csv.writer(outputfile, delimiter='|')
    for line in file2:
        if line[:1] == '>':
            row = line.strip().split('|')
            key = row[0][1:]
            if key in file1_data:
                output.writerow(row + [file1_data[key]])
        else:
            outputfile.write(line)