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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def parse(self):
 """Parse this Berksfile into a dict."""

        self.flush()
        self.seek(0)
        data = utils.ruby_lines(self.readlines())
        data = [tuple(j.strip() for j in line.split(None, 1))
                for line in data]
        datamap = {}
        for line in data:
            if len(line) == 1:
                datamap[line[0]] = True
            elif len(line) == 2:
                key, value = line
                if key == 'cookbook':
                    datamap.setdefault('cookbook', {})
                    value = [utils.ruby_strip(v) for v in value.split(',')]
                    lib, detail = value[0], value[1:]
                    datamap['cookbook'].setdefault(lib, {})
                    # if there is additional dependency data but its
                    # not the ruby hash, its the version constraint
                    if detail and not any("".join(detail).startswith(o)
                                          for o in self.berks_options):
                        constraint, detail = detail[0], detail[1:]
                        datamap['cookbook'][lib]['constraint'] = constraint
                    if detail:
                        for deet in detail:
                            opt, val = [
                                utils.ruby_strip(i)
                                for i in deet.split(':', 1)
                            ]
                            if not any(opt == o for o in self.berks_options):
                                raise ValueError(
                                    "Cookbook detail '%s' does not specify "
                                    "one of '%s'" % (opt, self.berks_options))
                            else:
                                datamap['cookbook'][lib][opt.strip(':')] = (
                                    utils.ruby_strip(val))
                elif key == 'source':
                    datamap.setdefault(key, [])
                    datamap[key].append(utils.ruby_strip(value))
                elif key:
                    datamap[key] = utils.ruby_strip(value)
        self.seek(0)
        return datamap