10 examples of 'python get value from dictionary if key exists' in Python

565
def TryGetValue(self,key,value):
566
 """ TryGetValue(self: IDictionary[TKey,TValue],key: TKey) -> (bool,TValue) """
567
 pass

433
class IReadOnlyList(IReadOnlyCollection[T], IEnumerable[T], IEnumerable):
434
    # no doc
435
    def __contains__(self, *args): #cannot find CLR method

316
def __getitem__(self, key):
317
    """Return the first data value for this key;
318
    raises KeyError if not found.
319
320
    :param key: The key to be looked up.
321
    :raise KeyError: if the key does not exist.
322
    """
323
    if key in self:
324
        lst = dict.__getitem__(self, key)
325
        if len(lst) > 0:
326
            return lst[0]
327
    if self.key_error_exception:
328
        raise self.key_error_exception(key)

5
def _find_dict_in_list(list_of_dict, key, val):
6
    """Given a list of dictionaries, return the first dictionary that has the
7
    given key:value pair.
8
    """
9
    try:
10
        for d in list_of_dict:
11
            if (key, val) in d.items():
12
                return d
13
    except TypeError:
14
        pass

102
def _find_key(d, key):
103
    if not d:
104
        return None
105
    for k, v in d.items()[:]:
106
        if k == key:
107
            return d
108
        else:
109
            result = _find_key(v, key)
110
            if result is not None:
111
                return result

31
def dict_lookup(dic, key_path, default=None):
32
    """
33
    Look up value in a nested dict
34
35
    Args:
36
        dic: The dictionary to search
37
        key_path: An iterable containing an ordered list of dict keys to
38
                  traverse
39
        default: Value to return in case nothing is found
40
41
    Returns:
42
        Value of the dict at the nested location given, or default if no value
43
        was found
44
    """
45
46
    for k in key_path:
47
        if k in dic:
48
            dic = dic[k]
49
        else:
50
            return default
51
    return dic

92
def getDic(self, key = 'process'):
93
    """return the list of processes of all active terminal"""
94
    return [self.dic[terminal][key] for terminal in self.dic if self.dic[terminal]['active']]

1
def contains_val(data, key, value):
2
    """
3
    check if certain key has certain value, return true if so and false otherwise
4
    """
5
    # try to get value variable from parser specific variables
6
    value = _ttp_["parser_object"].vars.get(value, value)
7
    if not value in data.get(key, ""):
8
        return data, False
9
    return data, None

22
def _get_value_by_path(source_dict, key_path,
23
                       ignore_key_error=False, default=""):
24
    """Get key value from nested dict by path.
25
26
    Args:
27
        source_dict: The dict that we look into.
28
        key_path: A list has the path of key. e.g. [parent_dict, child_dict, key_name].
29
        ignore_key_error: Ignore KeyError if the key is not found in provided path.
30
        default: Set default value if the key is not found in provided path.
31
32
    Returns:
33
        If key is found in provided path, it will be returned.
34
        If ignore_key_error is True, None will be returned.
35
        If default is defined and key is not found, default will be returned.
36
    """
37
38
    key_value = ""
39
    try:
40
        # Reduce key path, where it get value from nested dict.
41
        # a replacement for buildin reduce function.
42
        for key in key_path:
43
            if isinstance(source_dict.get(key), dict) and len(key_path) > 1:
44
                source_dict = source_dict.get(key)
45
                key_path = key_path[1:]
46
                _get_value_by_path(source_dict, key_path,
47
                                   ignore_key_error=ignore_key_error, default=default)
48
            else:
49
                key_value = source_dict[key]
50
51
    # How to set the key value, if the key was not found.
52
    except KeyError as key_name:
53
        if default:
54
            key_value = default
55
        elif not default and ignore_key_error:
56
            key_value = None
57
        elif not key_value and not ignore_key_error:
58
            sys.exit("The key %s is not found. Please remember, Python is case sensitive." % key_name)
59
    return key_value

67
def __getitem__(self, key):
68
    self.__missing__(key)
69
    return self.value