How to use the fastparquet.util.val_to_num function in fastparquet

cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)
        else:
            for (i, val) in enumerate(path.split("/")[:-1]):
                key = "dir%i" % i
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)

    for (key, v) in cats.items():
        # Check that no partition names map to the same value after
        # transformation by val_to_num
        raw = raw_cats[key]
        if len(v) != len(raw):
            conflicts_by_value = OrderedDict()
            for raw_val in raw_cats[key]:
                conflicts_by_value.setdefault(val_to_num(raw_val), set()).add(raw_val)
            conflicts = [
                c for k in conflicts_by_value.values() if len(k) > 1 for c in k
            ]
            raise ValueError("Partition names map to the same value: %s" % conflicts)
        vals_by_type = groupby_types(v)

        # Check that all partition names map to the same type after
        # transformation by val_to_num
        if len(vals_by_type) > 1:
            examples = [x[0] for x in vals_by_type.values()]
            warnings.warn(
                "Partition names coerce to values of different"
                " types, e.g. %s" % examples
            )
    return {k: list(v) for k, v in cats.items()}

"""Extract out fields and labels from directory names"""
    # can be factored out in fastparquet
    cats = OrderedDict()
    raw_cats = OrderedDict()

    for path in paths:
        s = ex_from_sep("/")
        if scheme == "hive":
            partitions = s.findall(path)
            for (key, val) in partitions:
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)
        else:
            for (i, val) in enumerate(path.split("/")[:-1]):
                key = "dir%i" % i
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)

    for (key, v) in cats.items():
        # Check that no partition names map to the same value after
        # transformation by val_to_num
        raw = raw_cats[key]
        if len(v) != len(raw):
            conflicts_by_value = OrderedDict()
            for raw_val in raw_cats[key]:
                conflicts_by_value.setdefault(val_to_num(raw_val), set()).add(raw_val)
            conflicts = [
                c for k in conflicts_by_value.values() if len(k) > 1 for c in k
            ]
            raise ValueError("Partition names map to the same value: %s" % conflicts)
        vals_by_type = groupby_types(v)

from fastparquet.util import ex_from_sep, val_to_num, groupby_types

    cats = OrderedDict()
    raw_cats = OrderedDict()

    for path in paths:
        s = ex_from_sep("/")
        if scheme == "hive":
            partitions = s.findall(path)
            for key, val in partitions:
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)
        else:
            for i, val in enumerate(path.split("/")[:-1]):
                key = "dir%i" % i
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)

    for key, v in cats.items():
        # Check that no partition names map to the same value after
        # transformation by val_to_num
        raw = raw_cats[key]
        if len(v) != len(raw):
            conflicts_by_value = OrderedDict()
            for raw_val in raw_cats[key]:
                conflicts_by_value.setdefault(val_to_num(raw_val), set()).add(raw_val)
            conflicts = [
                c for k in conflicts_by_value.values() if len(k) > 1 for c in k
            ]
            raise ValueError("Partition names map to the same value: %s" % conflicts)
        vals_by_type = groupby_types(v)

def _paths_to_cats(paths, scheme):
    """Extract out fields and labels from directory names"""
    # can be factored out in fastparquet
    cats = OrderedDict()
    raw_cats = OrderedDict()

    for path in paths:
        s = ex_from_sep("/")
        if scheme == "hive":
            partitions = s.findall(path)
            for (key, val) in partitions:
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)
        else:
            for (i, val) in enumerate(path.split("/")[:-1]):
                key = "dir%i" % i
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)

    for (key, v) in cats.items():
        # Check that no partition names map to the same value after
        # transformation by val_to_num
        raw = raw_cats[key]
        if len(v) != len(raw):
            conflicts_by_value = OrderedDict()
            for raw_val in raw_cats[key]:
                conflicts_by_value.setdefault(val_to_num(raw_val), set()).add(raw_val)
            conflicts = [

def _paths_to_cats(paths, scheme):
    """Extract out fields and labels from directory names"""
    # can be factored out in fastparquet
    from fastparquet.util import ex_from_sep, val_to_num, groupby_types

    cats = OrderedDict()
    raw_cats = OrderedDict()

    for path in paths:
        s = ex_from_sep("/")
        if scheme == "hive":
            partitions = s.findall(path)
            for key, val in partitions:
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)
        else:
            for i, val in enumerate(path.split("/")[:-1]):
                key = "dir%i" % i
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)

    for key, v in cats.items():
        # Check that no partition names map to the same value after
        # transformation by val_to_num
        raw = raw_cats[key]
        if len(v) != len(raw):
            conflicts_by_value = OrderedDict()
            for raw_val in raw_cats[key]:
                conflicts_by_value.setdefault(val_to_num(raw_val), set()).add(raw_val)
            conflicts = [

cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)
        else:
            for i, val in enumerate(path.split("/")[:-1]):
                key = "dir%i" % i
                cats.setdefault(key, set()).add(val_to_num(val))
                raw_cats.setdefault(key, set()).add(val)

    for key, v in cats.items():
        # Check that no partition names map to the same value after
        # transformation by val_to_num
        raw = raw_cats[key]
        if len(v) != len(raw):
            conflicts_by_value = OrderedDict()
            for raw_val in raw_cats[key]:
                conflicts_by_value.setdefault(val_to_num(raw_val), set()).add(raw_val)
            conflicts = [
                c for k in conflicts_by_value.values() if len(k) > 1 for c in k
            ]
            raise ValueError("Partition names map to the same value: %s" % conflicts)
        vals_by_type = groupby_types(v)

        # Check that all partition names map to the same type after
        # transformation by val_to_num
        if len(vals_by_type) > 1:
            import warnings

            examples = [x[0] for x in vals_by_type.values()]
            warnings.warn(
                "Partition names coerce to values of different"
                " types, e.g. %s" % examples
            )