FlatDict

FlatDict is a Python module for interacting with nested dicts as a single level dict with delimited keys. FlatDict supports Python 2.6+ and 3.2+.

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For example:

foo = {'foo': {'bar': 'baz', 'qux': 'corge'}}

is represented as:

{'foo:bar': 'baz',
 'foo:qux': 'corge'}

And can still be accessed as:

foo['foo']['bar']

and

foo['foo:bar']

Additionally, lists and tuples are also converted into dicts using enumerate().

For example:

d = {'list': ['a', 'b', 'c',]}

Will be flattened as follows:

flat = {'list:0': 'a', 'list:1': 'b', 'list:2': 'c'}

Installation

$ pip install flatdict

Example Use

import flatdict

values = {'foo': {'bar': {'baz': 0,
                          'qux': 1,
                          'corge': 2},
                  'grault': {'baz': 3,
                             'qux': 4,
                             'corge': 5}},
          'garply': {'foo': 0, 'bar': 1, 'baz': 2, 'qux': {'corge': 3}}}

flat = flatdict.FlatDict(values)

print flat['foo:bar:baz']

flat['test:value:key'] = 10

del flat['test']

for key in flat:
    print key

for values in flat.itervalues():
    print key

print repr(flat.as_dict())

Class Documentation

FlatDict is a dict object that allows for single level, delimited key/value pair mapping of nested dictionaries.

class flatdict.FlatDict(value=None, delimiter=None, former_type=<type 'dict'>)

FlatDict is a dictionary object that allows for single level, delimited key/value pair mapping of nested dictionaries. The default delimiter value is : but can be changed in the constructor or by calling FlatDict.set_delimiter.

DELIMITER = ':'

as_dict()

Return the flat dictionary as a dictionary.

Return type:dict

clear()

Remove all items from the flat dictionary.

copy()

Return a shallow copy of the flat dictionary.

Return type:flatdict.FlatDict

fromkeys(S[, v]) → New dict with keys from S and values equal to v.

v defaults to None.

get(key, d=None)

Return the value for key if key is in the flat dictionary, else default. If default is not given, it defaults to None, so that this method never raises a KeyError.

Parameters:

• key (mixed) – The key to get
• d (mixed) – The default value

Return type:

mixed

has_key(key)

Check to see if the flat dictionary has a specific key.

Parameters:key (mixed) – The key to check for Return type:bool

items()

Return a copy of the flat dictionary’s list of (key, value) pairs.

Note

CPython implementation detail: Keys and values are listed in an arbitrary order which is non-random, varies across Python implementations, and depends on the flat dictionary’s history of insertions and deletions.

Return type:list

iteritems()

Return an iterator over the flat dictionary’s (key, value) pairs. See the note for FlatDict.items().

Using iteritems() while adding or deleting entries in the flat dictionary may raise a RuntimeError or fail to iterate over all entries.

Return type:Iterator Raises:RuntimeError

iterkeys()

Return an iterator over the flat dictionary’s keys. See the note for FlatDict.items().

Using iterkeys() while adding or deleting entries in the flat dictionary may raise a RuntimeError or fail to iterate over all entries.

Return type:Iterator Raises:RuntimeError

itervalues()

Return an iterator over the flat dictionary’s values. See the note for FlatDict.items().

Using itervalues() while adding or deleting entries in the flat dictionary may raise a RuntimeError or fail to iterate over all entries.

Return type:Iterator Raises:RuntimeError

keys()

Return a copy of the flat dictionary’s list of keys. See the note for FlatDict.items().

Return type:list

pop(key, default=None)

If key is in the flat dictionary, remove it and return its value, else return default. If default is not given and key is not in the dictionary, a KeyError is raised.

Parameters:

• key (mixed) – The key name
• default (mixed) – The default value

Return type:

mixed

popitem() → (k, v), remove and return some (key, value) pair as a

2-tuple; but raise KeyError if D is empty.

set_delimiter(delimiter)

Override the default or passed in delimiter with a new value.

Parameters:delimiter (str) – The delimiter to use

setdefault(key, default)

If key is in the flat dictionary, return its value. If not, insert key with a value of default and return default. default defaults to None.

Parameters:

• key (mixed) – The key name
• default (mixed) – The default value

Return type:

mixed

update(other=None, **kwargs)

Update the flat dictionary with the key/value pairs from other, overwriting existing keys.

update() accepts either another flat dictionary object or an iterable of key/value pairs (as tuples or other iterables of length two). If keyword arguments are specified, the flat dictionary is then updated with those key/value pairs: d.update(red=1, blue=2).

Return type:None

values()

Return a copy of the flat dictionary’s list of values. See the note for FlatDict.items().

Return type:list

viewitems() → a set-like object providing a view on D's items

viewkeys() → a set-like object providing a view on D's keys

viewvalues() → an object providing a view on D's values