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Diffstat (limited to 'python/vyos/utils/dict.py')
| -rw-r--r-- | python/vyos/utils/dict.py | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/python/vyos/utils/dict.py b/python/vyos/utils/dict.py new file mode 100644 index 000000000..9484eacdd --- /dev/null +++ b/python/vyos/utils/dict.py @@ -0,0 +1,307 @@ +# Copyright 2023 VyOS maintainers and contributors <maintainers@vyos.io> +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2.1 of the License, or (at your option) any later version. +# +# This library is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library. If not, see <http://www.gnu.org/licenses/>. + +def colon_separated_to_dict(data_string, uniquekeys=False): + """ Converts a string containing newline-separated entries + of colon-separated key-value pairs into a dict. + + Such files are common in Linux /proc filesystem + + Args: + data_string (str): data string + uniquekeys (bool): whether to insist that keys are unique or not + + Returns: dict + + Raises: + ValueError: if uniquekeys=True and the data string has + duplicate keys. + + Note: + If uniquekeys=True, then dict entries are always strings, + otherwise they are always lists of strings. + """ + import re + key_value_re = re.compile('([^:]+)\s*\:\s*(.*)') + + data_raw = re.split('\n', data_string) + + data = {} + + for l in data_raw: + l = l.strip() + if l: + match = re.match(key_value_re, l) + if match and (len(match.groups()) == 2): + key = match.groups()[0].strip() + value = match.groups()[1].strip() + else: + raise ValueError(f"""Line "{l}" could not be parsed a colon-separated pair """, l) + if key in data.keys(): + if uniquekeys: + raise ValueError("Data string has duplicate keys: {0}".format(key)) + else: + data[key].append(value) + else: + if uniquekeys: + data[key] = value + else: + data[key] = [value] + else: + pass + + return data + +def mangle_dict_keys(data, regex, replacement, abs_path=None, no_tag_node_value_mangle=False): + """ Mangles dict keys according to a regex and replacement character. + Some libraries like Jinja2 do not like certain characters in dict keys. + This function can be used for replacing all offending characters + with something acceptable. + + Args: + data (dict): Original dict to mangle + regex, replacement (str): arguments to re.sub(regex, replacement, ...) + abs_path (list): if data is a config dict and no_tag_node_value_mangle is True + then abs_path should be the absolute config path to the first + keys of data, non-inclusive + no_tag_node_value_mangle (bool): do not mangle keys of tag node values + + Returns: dict + """ + import re + from vyos.xml_ref import is_tag_value + + if abs_path is None: + abs_path = [] + + new_dict = type(data)() + + for k in data.keys(): + if no_tag_node_value_mangle and is_tag_value(abs_path + [k]): + new_key = k + else: + new_key = re.sub(regex, replacement, k) + + value = data[k] + + if isinstance(value, dict): + new_dict[new_key] = mangle_dict_keys(value, regex, replacement, + abs_path=abs_path + [k], + no_tag_node_value_mangle=no_tag_node_value_mangle) + else: + new_dict[new_key] = value + + return new_dict + +def _get_sub_dict(d, lpath): + k = lpath[0] + if k not in d.keys(): + return {} + c = {k: d[k]} + lpath = lpath[1:] + if not lpath: + return c + elif not isinstance(c[k], dict): + return {} + return _get_sub_dict(c[k], lpath) + +def get_sub_dict(source, lpath, get_first_key=False): + """ Returns the sub-dict of a nested dict, defined by path of keys. + + Args: + source (dict): Source dict to extract from + lpath (list[str]): sequence of keys + + Returns: source, if lpath is empty, else + {key : source[..]..[key]} for key the last element of lpath, if exists + {} otherwise + """ + if not isinstance(source, dict): + raise TypeError("source must be of type dict") + if not isinstance(lpath, list): + raise TypeError("path must be of type list") + if not lpath: + return source + + ret = _get_sub_dict(source, lpath) + + if get_first_key and lpath and ret: + tmp = next(iter(ret.values())) + if not isinstance(tmp, dict): + raise TypeError("Data under node is not of type dict") + ret = tmp + + return ret + +def dict_search(path, dict_object): + """ Traverse Python dictionary (dict_object) delimited by dot (.). + Return value of key if found, None otherwise. + + This is faster implementation then jmespath.search('foo.bar', dict_object)""" + if not isinstance(dict_object, dict) or not path: + return None + + parts = path.split('.') + inside = parts[:-1] + if not inside: + if path not in dict_object: + return None + return dict_object[path] + c = dict_object + for p in parts[:-1]: + c = c.get(p, {}) + return c.get(parts[-1], None) + +def dict_search_args(dict_object, *path): + # Traverse dictionary using variable arguments + # Added due to above function not allowing for '.' in the key names + # Example: dict_search_args(some_dict, 'key', 'subkey', 'subsubkey', ...) + if not isinstance(dict_object, dict) or not path: + return None + + for item in path: + if item not in dict_object: + return None + dict_object = dict_object[item] + return dict_object + +def dict_search_recursive(dict_object, key, path=[]): + """ Traverse a dictionary recurisvely and return the value of the key + we are looking for. + + Thankfully copied from https://stackoverflow.com/a/19871956 + + Modified to yield optional path to found keys + """ + if isinstance(dict_object, list): + for i in dict_object: + new_path = path + [i] + for x in dict_search_recursive(i, key, new_path): + yield x + elif isinstance(dict_object, dict): + if key in dict_object: + new_path = path + [key] + yield dict_object[key], new_path + for k, j in dict_object.items(): + new_path = path + [k] + for x in dict_search_recursive(j, key, new_path): + yield x + +def dict_to_list(d, save_key_to=None): + """ Convert a dict to a list of dicts. + + Optionally, save the original key of the dict inside + dicts stores in that list. + """ + def save_key(i, k): + if isinstance(i, dict): + i[save_key_to] = k + return + elif isinstance(i, list): + for _i in i: + save_key(_i, k) + else: + raise ValueError(f"Cannot save the key: the item is {type(i)}, not a dict") + + collect = [] + + for k,_ in d.items(): + item = d[k] + if save_key_to is not None: + save_key(item, k) + if isinstance(item, list): + collect += item + else: + collect.append(item) + + return collect + +def dict_to_paths(d: dict) -> list: + """ Generator to return list of paths from dict of list[str]|str + """ + def func(d, path): + if isinstance(d, dict): + if not d: + yield path + for k, v in d.items(): + for r in func(v, path + [k]): + yield r + elif isinstance(d, list): + for i in d: + for r in func(i, path): + yield r + elif isinstance(d, str): + yield path + [d] + else: + raise ValueError('object is not a dict of strings/list of strings') + for r in func(d, []): + yield r + +def check_mutually_exclusive_options(d, keys, required=False): + """ Checks if a dict has at most one or only one of + mutually exclusive keys. + """ + present_keys = [] + + for k in d: + if k in keys: + present_keys.append(k) + + # Un-mangle the keys to make them match CLI option syntax + from re import sub + orig_keys = list(map(lambda s: sub(r'_', '-', s), keys)) + orig_present_keys = list(map(lambda s: sub(r'_', '-', s), present_keys)) + + if len(present_keys) > 1: + raise ValueError(f"Options {orig_keys} are mutually-exclusive but more than one of them is present: {orig_present_keys}") + + if required and (len(present_keys) < 1): + raise ValueError(f"At least one of the following options is required: {orig_keys}") + +class FixedDict(dict): + """ + FixedDict: A dictionnary not allowing new keys to be created after initialisation. + + >>> f = FixedDict(**{'count':1}) + >>> f['count'] = 2 + >>> f['king'] = 3 + File "...", line ..., in __setitem__ + raise ConfigError(f'Option "{k}" has no defined default') + """ + + from vyos import ConfigError + + def __init__(self, **options): + self._allowed = options.keys() + super().__init__(**options) + + def __setitem__(self, k, v): + """ + __setitem__ is a builtin which is called by python when setting dict values: + >>> d = dict() + >>> d['key'] = 'value' + >>> d + {'key': 'value'} + + is syntaxic sugar for + + >>> d = dict() + >>> d.__setitem__('key','value') + >>> d + {'key': 'value'} + """ + if k not in self._allowed: + raise ConfigError(f'Option "{k}" has no defined default') + super().__setitem__(k, v) |