Python wildcard apply / glob apply

glob_apply.py

# MIT LICENSED
# Author: jwilson8767
import collections


def glob_apply(obj, paths, fn: callable, **kwargs) -> None:
    """
    Iterates a deeply nested structure using dot-notation wildcard paths.

    :param obj: The List/Sequence or Dict/Mapping to iterate
    :param paths: A single dot-notation path like "some_obj.*.label" or a list of paths like ["some_obj.*.label", "some_obj.*.items.*.label"]
    :param fn: The function to apply, should return the new value or mutated object.
    """
    full_path = None

    def _map_seq_enumerate(obj):
        if isinstance(obj, collections.Sequence) and not isinstance(obj, str):
            return enumerate(obj)
        if isinstance(obj, collections.Mapping):
            return obj.items()
        return [] # return empty

    def _glob_apply(obj, path):
        if obj is None:
            return
        try:
            if len(path) == 1:
                if path[0] == '*':
                    for i, _ in _map_seq_enumerate(obj):
                        obj[i] = fn(obj[i], **kwargs)
                elif path[0] in obj:
                    obj[path[0]] = fn(obj[path[0]], **kwargs)
                else:
                    return
            else:
                if path[0] == '*':
                    for i, _ in _map_seq_enumerate(obj):
                        _glob_apply(obj[i], path[1:])
                else:
                    if path[0] in obj:
                        _glob_apply(obj[path[0]], path[1:])
        except TypeError as ex:
            if str(ex) == 'list indices must be integers or slices, not str':
                raise ValueError('Path "{}" could not be recursed because a list object was encountered where a dict was expected. Try adding ".*" before ".{}" '.format(full_path, path[0]))
            else:
                raise ex


    if isinstance(paths, str):
        paths = [paths]
    for _path in paths:
        full_path = _path
        _glob_apply(obj, full_path.split('.'))

# Example usage:
def wrap_parens(obj):
  return '('+obj+')'


my_massively_nested_object = {
  'foo': {
     'items': [
    {'label': 'bar'},
    {'label': 'barr'},
    # ...
  ]},
  'foo2':  {
    'items': [
    {'label': '2bar'},
    {'label': '2barr'},
    # ...
  ]}
}

glob_apply(my_massively_nested_object, '*.items.*.label', wrap_parens);  # obj, path, func

"""
 {
  'foo': {
     'items': [
    {'label': '(bar)'},
    {'label': '(barr)'},
    # ...
  ]}
  'foo2':  {
    'items': [
    {'label': '(2bar)'},
    {'label': '(2barr)'},
    # ...
  ]}
};
"""