ansible-later/testenv/lib/python2.7/site-packages/anyconfig/dicts.py

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2019-04-23 11:04:27 +00:00
#
# Forked from m9dicts.{api,dicts}.
#
# Copyright (C) 2011 - 2015 Red Hat, Inc.
# Copyright (C) 2011 - 2017 Satoru SATOH <ssato redhat.com>
# License: MIT
#
r"""Utility functions to operate on mapping objects such as get, set and merge.
.. versionadded: 0.8.3
define _update_* and merge functions based on classes in
:mod:`m9dicts.dicts`
"""
from __future__ import absolute_import
import functools
import operator
import re
import anyconfig.utils
# Merge strategies:
MS_REPLACE = "replace"
MS_NO_REPLACE = "noreplace"
MS_DICTS = "merge_dicts"
MS_DICTS_AND_LISTS = "merge_dicts_and_lists"
MERGE_STRATEGIES = (MS_REPLACE, MS_NO_REPLACE, MS_DICTS, MS_DICTS_AND_LISTS)
PATH_SEPS = ('/', '.')
_JSNP_GET_ARRAY_IDX_REG = re.compile(r"(?:0|[1-9][0-9]*)")
_JSNP_SET_ARRAY_IDX = re.compile(r"(?:0|[1-9][0-9]*|-)")
def _jsnp_unescape(jsn_s):
"""
Parse and decode given encoded JSON Pointer expression, convert ~1 to
/ and ~0 to ~.
.. note:: JSON Pointer: http://tools.ietf.org/html/rfc6901
>>> _jsnp_unescape("/a~1b")
'/a/b'
>>> _jsnp_unescape("~1aaa~1~0bbb")
'/aaa/~bbb'
"""
return jsn_s.replace('~1', '/').replace('~0', '~')
def _split_path(path, seps=PATH_SEPS):
"""
Parse path expression and return list of path items.
:param path: Path expression may contain separator chars.
:param seps: Separator char candidates.
:return: A list of keys to fetch object[s] later.
>>> assert _split_path('') == []
>>> assert _split_path('/') == [''] # JSON Pointer spec expects this.
>>> for p in ('/a', '.a', 'a', 'a.'):
... assert _split_path(p) == ['a'], p
>>> assert _split_path('/a/b/c') == _split_path('a.b.c') == ['a', 'b', 'c']
>>> assert _split_path('abc') == ['abc']
"""
if not path:
return []
for sep in seps:
if sep in path:
if path == sep: # Special case, '/' or '.' only.
return ['']
return [x for x in path.split(sep) if x]
return [path]
def mk_nested_dic(path, val, seps=PATH_SEPS):
"""
Make a nested dict iteratively.
:param path: Path expression to make a nested dict
:param val: Value to set
:param seps: Separator char candidates
>>> mk_nested_dic("a.b.c", 1)
{'a': {'b': {'c': 1}}}
>>> mk_nested_dic("/a/b/c", 1)
{'a': {'b': {'c': 1}}}
"""
ret = None
for key in reversed(_split_path(path, seps)):
ret = {key: val if ret is None else ret.copy()}
return ret
def get(dic, path, seps=PATH_SEPS, idx_reg=_JSNP_GET_ARRAY_IDX_REG):
"""getter for nested dicts.
:param dic: a dict[-like] object
:param path: Path expression to point object wanted
:param seps: Separator char candidates
:return: A tuple of (result_object, error_message)
>>> d = {'a': {'b': {'c': 0, 'd': [1, 2]}}, '': 3}
>>> assert get(d, '/') == (3, '') # key becomes '' (empty string).
>>> assert get(d, "/a/b/c") == (0, '')
>>> sorted(get(d, "a.b")[0].items())
[('c', 0), ('d', [1, 2])]
>>> (get(d, "a.b.d"), get(d, "/a/b/d/1"))
(([1, 2], ''), (2, ''))
>>> get(d, "a.b.key_not_exist") # doctest: +ELLIPSIS
(None, "'...'")
>>> get(d, "/a/b/d/2")
(None, 'list index out of range')
>>> get(d, "/a/b/d/-") # doctest: +ELLIPSIS
(None, 'list indices must be integers...')
"""
items = [_jsnp_unescape(p) for p in _split_path(path, seps)]
if not items:
return (dic, '')
try:
if len(items) == 1:
return (dic[items[0]], '')
prnt = functools.reduce(operator.getitem, items[:-1], dic)
arr = anyconfig.utils.is_list_like(prnt) and idx_reg.match(items[-1])
return (prnt[int(items[-1])], '') if arr else (prnt[items[-1]], '')
except (TypeError, KeyError, IndexError) as exc:
return (None, str(exc))
def set_(dic, path, val, seps=PATH_SEPS):
"""setter for nested dicts.
:param dic: a dict[-like] object support recursive merge operations
:param path: Path expression to point object wanted
:param seps: Separator char candidates
>>> d = dict(a=1, b=dict(c=2, ))
>>> set_(d, 'a.b.d', 3)
>>> d['a']['b']['d']
3
"""
merge(dic, mk_nested_dic(path, val, seps), ac_merge=MS_DICTS)
def _are_list_like(*objs):
"""
>>> _are_list_like([], (), [x for x in range(10)], (x for x in range(4)))
True
>>> _are_list_like([], {})
False
>>> _are_list_like([], "aaa")
False
"""
return all(anyconfig.utils.is_list_like(obj) for obj in objs)
def _update_with_replace(self, other, key, val=None, **options):
"""
Replace value of a mapping object `self` with `other` has if both have same
keys on update. Otherwise, just keep the value of `self`.
:param self: mapping object to update with `other`
:param other: mapping object to update `self`
:param key: key of mapping object to update
:param val: value to update self alternatively
:return: None but `self` will be updated
"""
self[key] = other[key] if val is None else val
def _update_wo_replace(self, other, key, val=None, **options):
"""
Never update (replace) the value of `self` with `other`'s, that is, only
the values `self` does not have its key will be added on update.
:param self: mapping object to update with `other`
:param other: mapping object to update `self`
:param key: key of mapping object to update
:param val: value to update self alternatively
:return: None but `self` will be updated
"""
if key not in self:
_update_with_replace(self, other, key, val=val)
def _merge_list(self, key, lst):
"""
:param key: self[key] will be updated
:param lst: Other list to merge
"""
self[key] += [x for x in lst if x not in self[key]]
def _merge_other(self, key, val):
"""
:param key: self[key] will be updated
:param val: Other val to merge (update/replace)
"""
self[key] = val # Just overwrite it by default implementation.
def _update_with_merge(self, other, key, val=None, merge_lists=False,
**options):
"""
Merge the value of self with other's recursively. Behavior of merge will be
vary depends on types of original and new values.
- mapping vs. mapping -> merge recursively
- list vs. list -> vary depends on `merge_lists`. see its description.
:param other: a dict[-like] object or a list of (key, value) tuples
:param key: key of mapping object to update
:param val: value to update self[key]
:param merge_lists:
Merge not only dicts but also lists. For example,
[1, 2, 3], [3, 4] ==> [1, 2, 3, 4]
[1, 2, 2], [2, 4] ==> [1, 2, 2, 4]
:return: None but `self` will be updated
"""
if val is None:
val = other[key]
if key in self:
val0 = self[key] # Original value
if anyconfig.utils.is_dict_like(val0): # It needs recursive updates.
merge(self[key], val, merge_lists=merge_lists, **options)
elif merge_lists and _are_list_like(val, val0):
_merge_list(self, key, val)
else:
_merge_other(self, key, val)
else:
self[key] = val
def _update_with_merge_lists(self, other, key, val=None, **options):
"""
Similar to _update_with_merge but merge lists always.
:param self: mapping object to update with `other`
:param other: mapping object to update `self`
:param key: key of mapping object to update
:param val: value to update self alternatively
:return: None but `self` will be updated
"""
_update_with_merge(self, other, key, val=val, merge_lists=True, **options)
_MERGE_FNS = {MS_REPLACE: _update_with_replace,
MS_NO_REPLACE: _update_wo_replace,
MS_DICTS: _update_with_merge,
MS_DICTS_AND_LISTS: _update_with_merge_lists}
def _get_update_fn(strategy):
"""
Select dict-like class based on merge strategy and orderness of keys.
:param merge: Specify strategy from MERGE_STRATEGIES of how to merge dicts.
:return: Callable to update objects
"""
if strategy is None:
strategy = MS_DICTS
try:
return _MERGE_FNS[strategy]
except KeyError:
if callable(strategy):
return strategy
raise ValueError("Wrong merge strategy: %r" % strategy)
def merge(self, other, ac_merge=MS_DICTS, **options):
"""
Update (merge) a mapping object `self` with other mapping object or an
iterable yields (key, value) tuples based on merge strategy `ac_merge`.
:param others: a list of dict[-like] objects or (key, value) tuples
:param another: optional keyword arguments to update self more
:param ac_merge: Merge strategy to choose
"""
_update_fn = _get_update_fn(ac_merge)
if hasattr(other, "keys"):
for key in other:
_update_fn(self, other, key, **options)
else:
try:
for key, val in other:
_update_fn(self, other, key, val=val, **options)
except (ValueError, TypeError) as exc: # Re-raise w/ info.
raise type(exc)("%s other=%r" % (str(exc), other))
def _make_recur(obj, make_fn, ac_ordered=False, ac_dict=None, **options):
"""
:param obj: A mapping objects or other primitive object
:param make_fn: Function to make/convert to
:param ac_ordered: Use OrderedDict instead of dict to keep order of items
:param ac_dict: Callable to convert `obj` to mapping object
:param options: Optional keyword arguments.
:return: Mapping object
"""
if ac_dict is None:
ac_dict = anyconfig.compat.OrderedDict if ac_ordered else dict
return ac_dict((k, None if v is None else make_fn(v, **options))
for k, v in obj.items())
def _make_iter(obj, make_fn, **options):
"""
:param obj: A mapping objects or other primitive object
:param make_fn: Function to make/convert to
:param options: Optional keyword arguments.
:return: Mapping object
"""
return type(obj)(make_fn(v, **options) for v in obj)
def convert_to(obj, ac_ordered=False, ac_dict=None, **options):
"""
Convert a mapping objects to a dict or object of `to_type` recursively.
Borrowed basic idea and implementation from bunch.unbunchify. (bunch is
distributed under MIT license same as this.)
:param obj: A mapping objects or other primitive object
:param ac_ordered: Use OrderedDict instead of dict to keep order of items
:param ac_dict: Callable to convert `obj` to mapping object
:param options: Optional keyword arguments.
:return: A dict or OrderedDict or object of `cls`
>>> OD = anyconfig.compat.OrderedDict
>>> convert_to(OD((('a', 1) ,)), cls=dict)
{'a': 1}
>>> convert_to(OD((('a', OD((('b', OD((('c', 1), ))), ))), )), cls=dict)
{'a': {'b': {'c': 1}}}
"""
options.update(ac_ordered=ac_ordered, ac_dict=ac_dict)
if anyconfig.utils.is_dict_like(obj):
return _make_recur(obj, convert_to, **options)
if anyconfig.utils.is_list_like(obj):
return _make_iter(obj, convert_to, **options)
return obj
# vim:sw=4:ts=4:et: