libervia-backend/src/tools/common/data_format.py

81 lines
2.7 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
# SAT: a jabber client
# Copyright (C) 2009-2016 Jérôme Poisson (goffi@goffi.org)
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program 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 Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
""" tools common to backend and frontends """
from sat.core import exceptions
def dict2iter(name, dict_, pop=False):
"""iterate into a list serialised in a dict
name is the name of the key.
Serialisation is done with [name] [name#1] [name#2] and so on
e.g.: if name is 'group', keys are group, group#1, group#2, ...
iteration stop at first missing increment
Empty values are possible
@param name(unicode): name of the key
@param mb_data (dict): dictionary with the serialised list
@param pop(bool): if True, remove the value from dict
@return iter: iterate through the deserialised list
"""
if pop:
get=lambda d,k: d.pop(k)
else:
get=lambda d,k: d[k]
try:
yield get(dict_,name)
except KeyError:
return
else:
idx = 1
while True:
try:
yield get(dict_,u'{}#{}'.format(name, idx))
except KeyError:
return
else:
idx += 1
def iter2dict(name, iter_, dict_=None, check_conflict=True):
"""Fill a dict with values from an iterable
name is used to serialise iter_, in the same way as in [dict2iter]
Build from the tags a dict using the microblog data format.
@param name(unicode): key to use for serialisation
e.g. "group" to have keys "group", "group#1", "group#2", ...
@param iter_(iterable): values to store
@param dict_(None, dict): dictionary to fill, or None to create one
@param check_conflict(bool): if True, raise an exception in case of existing key
@return (dict): filled dict, or newly created one
@raise exceptions.ConflictError: a needed key already exists
"""
if dict_ is None:
dict_ = {}
for idx, value in enumerate(iter_):
if idx == 0:
key = name
else:
key = u'{}#{}'.format(name, idx)
if check_conflict and key in dict_:
raise exceptions.ConflictError
dict_[key] = value
return dict