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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 dzn2dict(dzn, *, rebase_arrays=True, types=None, return_enums=False):
 """Parses a dzn string or file into a dictionary of variable assignments. Parameters dzn : str A dzn content string or a path to a dzn file. rebase_arrays : bool Whether to return arrays as zero-based lists or to return them as dictionaries, preserving the original index-sets. types : dict Dictionary of variable types. Types can either be dictionaries, as returned by the ``minizinc --model-types-only``, or strings containing a type in dzn format. If the type is a string, it can either be the name of an enum type or one of the following: ``bool``, ``int``, ``float``, ``enum``, ``set of <type>``, ``array[<index_sets>] of <type>``. The default value for ``var_types`` is ``None``, in which case the type of most dzn assignments will be inferred automatically from the value. Enum values can only be parsed if their respective types are available. return_enums : bool Whether to return the parsed enum types included in the dzn content. Returns ------- dict A dictionary containing the variable assignments parsed from the input file or string. """

    dzn_ext = os.path.splitext(dzn)[1]
    if dzn_ext == '.dzn':
        with open(dzn) as f:
            dzn = f.read()

    var_types = None
    if types:
        var_types = {}
        for var, var_type in types.items():
            if isinstance(var_type, str):
                var_types[var] = _to_var_type(var, var_type)
            elif isinstance(var_type, dict):
                var_types[var] = var_type
            else:
                err = 'Type of variable {} must be a string or a dict.'
                raise ValueError(err.format(var))

    enum_types = None
    if var_types:
        enum_types = []
        for var, var_type in var_types.items():
            if 'enum_type' in var_type and var_type['enum_type'] == var:
                enum_types.append(var)

    var_list = []
    dzn = _comm_p.sub('\n', dzn)
    stmts = _stmt_p.findall(dzn)
    for stmt in stmts:
        var_m = _var_p.match(stmt)
        if var_m:
            var = var_m.group('var')
            val = var_m.group('val')
            var_list.append((var, val))
        else:
            raise ValueError(
                'Unsupported parsing for statement:\n{}'.format(repr(stmt))
            )

    enums = None
    if enum_types:
        enums = {}
        remaining = []
        while len(var_list) > 0:
            var, val = var_list.pop(0)
            if var in enum_types:
                enum = None
                enum_m = _enum_p.match(val)
                if enum_m:
                    vals = enum_m.group('vals').strip()
                    if vals:
                        enum_vals = _parse_enum_vals(vals.split(','))
                        enum = IntEnum(
                            var, {v: i + 1 for i, v in enumerate(enum_vals)}
                        )
                if enum is None:
                    raise ValueError(
                        'Cannot parse enum type \'{} = {}\'.'.format(var, val)
                    )
                enums[var] = enum
            else:
                remaining.append((var, val))
        var_list = remaining

    assign = {}
    for var, val in var_list:
        var_type = None
        if var_types:
            var_type = var_types.get(var, None)
        assign[var] = parse_value(
            val, var_type=var_type, enums=enums, rebase_arrays=rebase_arrays
        )

    if return_enums and enums:
        assign.update(enums)

    return assign