usage: ./program.py --xml ./data.txt or ./program.py --json ./data.txt

data.txt

0: a:1, x:2, w:3
1: b:1, c:3, t:5

program.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import sys
import getopt
import json
from lxml import etree


class Program:

    def __init__(self, file):
        self.file_content = []
        self.dict = {}
        self.read_file(file)

    def read_file(self, file):
        with open(file) as f:
            for line in f:
                self.file_content.append(line.strip().replace(' ', ''))

    def create_dict(self):
        for line in self.file_content:
            self.dict[int(line.split(':', 1)[0])] = {
                dic.split(':')[0]: dic.split(':')[1] for dic in
                (line.split(':', 1)[1]).split(',')}

    def as_json(self):
        return json.dumps(self.dict)

    def as_xml(self):
        root = etree.Element('program')
        for m, d in self.dict.items():
            minor = etree.Element('minor')
            minor.set('nr', str(m))
            for key, val in d.items():
                child = etree.Element(key)
                child.text = str(val)
                minor.append(child)
            root.append(minor)
        return etree.tostring(root, pretty_print=True)


if __name__ == "__main__":
    try:
        opts, args = getopt.getopt(sys.argv[1:], "jx", ["json", "xml"])
        if len(args) != 1:
            print 'You have to specify file path!'
            sys.exit(2)
    except getopt.GetoptError as err:
        print str(err)
        sys.exit(2)

    program = Program(args[0])
    program.create_dict()
    for o, v in opts:
        if o in ('-j', '--json'):
            print program.as_json()
        if o in ('-x', '--xml'):
            print program.as_xml()

./program.py --xml ./data.txt
./program.py --json ./data.txt
./program.py --json --xml ./data.txt