number_pad_spaces.py

#!/usr/bin/env python

"""Add spaces before numbers to pad them all to the same width

Usage:
    %program <input> <output> <spaces>

<spaces>  number of spaces including zeros for sequence number (default: 6)"""

# Importing modules
import sys

# Parsing command line
try:
    in_file = open(sys.argv[1])
    out_file = open(sys.argv[2], "w")
except:
    print __doc__
    sys.exit[0]

try:
    num_spaces = int(sys.argv[3])
except:
    num_spaces = 6

# Main
if __name__ == '__main__':
    for line in in_file:
        l = line.strip()
        if l != "":
            added_spaces = num_spaces - len(l)
            if added_spaces > 0:
                out_file.write(" " * added_spaces + l + "\n")
            else:
                out_file.write(line)

    in_file.close()
    out_file.close()