add_zeroes.py

#!/usr/bin/env python

from sys import argv

with open(argv[1], 'U') as input_f, open(argv[2], 'w') as output_f:
    for line in input_f:
        # Write comment/header line(s) to output file unmodified
        if line.startswith('#'):
            output_f.write(line)
            continue

        sample_id, other = line.split('\t', 1)

        # Check if this ID is just a number or a number with a decimal point
        try:
            test = float(sample_id)
        except ValueError:
            # If not, then it's a BLANK or something, so write it unmodified
            output_f.write(line)
            continue

        # If it has a dot, then it should be 15 digits long (9 for barcode,
        # dot, and 5-digit unique number from old database)
        if '.' in sample_id:
            sample_id = sample_id.zfill(15)
        else:
            # If it's just a number, then it should be a 9-digit number
            sample_id = sample_id.zfill(9)

        output_f.write(sample_id + '\t' + other)