Python-like string format in JavaScript

string-format.js

/**
 * Python-like string format function
 * @param {String} str - Template string.
 * @param {Object} data - Data to insert strings from.
 * @returns {String}
 */
var format = function(str, data) {
  var re = /{([^{}]+)}/g;

  return str.replace(/{([^{}]+)}/g, function(match, val) {
    var prop = data;
    val.split('.').forEach(function(key) {
      prop = prop[key];
    });

    return prop;
  });
};

/**
 * Python-like format method
 * @param {Object} data - Data to insert strings from.
 * @returns {String}
 */
String.prototype.format = function(data) {
  return format(this, data);
};

var data =  {
  'result': '2-1',
  'team a': {
    name: 'Manchester United',
    best: 'Ryan Giggs'
  },
  'team b': {
    name: 'Chelsea',
    best: 'Frank Lampard'
  }
};
var r = format(
  '{team a.name} won {result} against {team b.name},\n' +
  'Best players: {team a.best}, {team b.best}',
  data
);
console.log(r);

r = format(
  'US Open Final: {0} vs {1}', [
    'New York Red Bulls', 'Los Angeles Galaxy'
  ]
);
console.log(r);

r  = '{team a}\'s {player} scored a goal against {team b}'.format({
  'team a': 'Manchester United',
  'team b': 'Arsenal',
  'player': 'Wayne Rooney'
});
console.log(r);