Skip to content

DefDict

Jump to bottom
Suke0811 edited this page Aug 17, 2022 · 18 revisions

DefDict is an extension of a dictionary, but with definitions + typing like in TypedDict.

Key differences are:

  • Many options to set the values
  • Many ways to output values
  • Filter out based on a subset of keys
  • Convert compatible definitions to its own definitions
  • Object-oriented structure and native nested DefDict handling

Create a new DefDict

# x,y,z and they are float
# this will enforce all values are float. Simply float(value) will be called at this moment.
pos = DefDict(dict(x=float,y=float,z=float))

# rotation
rot = DefDict(dict(qx=float,qy=float,qz=float, qw=float))
# x,y,z and rotation
pos_rot = DefDict((dict(x=float,y=float,z=float),
                   dict(qx=float,qy=float,qz=float, qw=float))) # Tuple of two dicts

Set values

d = DefDict(dict(x=float,y=float,z=float))
# set value
d.set({'x': 1, 'y':2, 'z':3})
# or you can use equality, but not recommended to avoid typos (missing .data, i.e.) 
d.data = {'x': 1, 'y':2,'z':3}
# you can use tuple, list, ndarray, or just single value
d.set(('x',1))
d.set([1,2,3])          # positional assignment
d.set(np.array[1,2,3])  # positional assignment
d.set(1)                # positional assignment
# you can do like normal dict
d['x'] = 1

Get values:

d = DefDict(dict(x=float,y=float,z=float))  

d.set({'x': 1, 'y':2, 'z':3})
d.dict() -> {'x': 1, 'y':2, 'z':3}
d.data() -> {'x': 1, 'y':2, 'z':3}
d.list() -> [1,2,3]
d.ndarray()  -> ndarray([1,2,3])
d.ndtall()  -> ndarray([[1],[2],[3]]) #tall vector
d.ndarray((1,3))  -> # reshaped ndarray

# You can do like normal dict
d.get('x') -> 1
d['x'] -> 1

# For keys
d.list_keys()  -> ['x','y','z']

# you can get certain values only:
d.get('x')           -> {'x':1}
d.get(['x','y'])     -> {'x': 1, 'y':2}
d.get({'x':0,'y':0}) -> {'x': 1, 'y':2}  # ignore values in the original dictionary

You can filter and get:

d.filter(['x','y']).list()    -> [1,2]
d.filte(['x','y']).ndarray() -> ndarray([1,2]) 
# or any operations you can do with DefDict
# You can set values and it'll be reflected to the original DefDict
d.filter('z').set(10) -> {'z': 10}
print(d) -> {'x': 1, 'y':2, 'z':10}

Other dict methods are implemented

# you can use DefDict as if it is just a dictionary
d.values()
d.keys()
d.items()
d.update()      # same behavior as set()
d.setdefault()  # same behavior as set()
d.clear()       # also clear definitions
d.pop()         # re-initialize given key
d.popitem()     # re-initialize given key

DefDict has shallow and deep copy options:

# shallow copy
d_shallow = d.copy()  # the same as dict.copy() behavior
# deep copy
d_deep = d.clone()    # not in dict

Print

You can see the contents by simply doing

print(d) -> {'x': 1, 'y':2, 'z':3}

Object-oriented: Prefixing/Suffixing and nested DefDict

Prefixing

You want keys to be descriptive and using numbers as a key is not so great. So you can prefix the keys like

print(d_j)  -> {'j.0': 1, 'j.1': 2,'j.2': 3}       # joint 0, 1, 2
# or 
print(d_ID) -> {'ID.11': 1, 'ID.12': 2,'ID.13': 3}    # Motor ID 11, 12,  13

But this is difficult to use programmatically because you always need to create a key. This is why DefDict has prefixing:

d_j = DefDict({'j.0': 1, 'j.1': 2,'j.2': 3}, prefixes='j')
d_j.j() = {'0': 1, '1': 2,'2': 3}
# or you can specify a sub set of them
d_j.j([1,2]) = {'1': 2,'2': 3}
d_j.j(1) = {'1': 2}
d_ID = DefDict({'ID.11': 1, 'ID.12': 2,'ID.13': 3}, prefixes=['ID']) # you can hand over list of prefixes
d_ID.ID() = {'11': 1, '12': 2,'13': 3}
# or you can specify a sub set of them
d_ID.ID([11,12]) = {'11': 2,'12': 3}
d_ID.ID(11) = {'11': 2}

Suffixing

A similar thing is possible for the key itself

d = DefDict({'pos': 1, 'vel':2, 'acc':3}, suffixes=['pos', 'vel', 'acc'])
d.pos -> 1
d.vel -> 2
d.acc -> 3

But this is more useful when DefDict is nested

Nested DefDict

You can nest DefDict, but you can easily get or set the values using prefixing and suffixing:

DEF = {'pos': 1, 'vel':2, 'acc':3}
d_j = DefDict({'j.0': DefDict(DEF), 'j.1': DefDict(DEF),'j.2': DefDict(DEF)}, prefixes='j', suffixes=DEF) # DEF is dict and only keys are used
print(d_j)  -> {'j.0': {'pos': 1, 'vel':2, 'acc':3}, 'j.1': {'pos': 1, 'vel':2, 'acc':3},'j.2': {'pos': 1, 'vel':2, 'acc':3}}

This would be very informative, but very difficult to deal with. But using suffixing:

d_j.pos()      -> {'j.0': 1, 'j.1': 1,'j.2': 1}
d_j.j().pos()  -> {'0': 1, '1': 1,'2': 1}
d_j.j(2).pos() -> {'2': 1}
d_j.j(0)       -> {'j.0': {'pos': 1, 'vel':2, 'acc':3}}
# You can use any method in DefDict in addition to suffixing
d_j.j().vel().list() -> [2,2,2]

Of course, you can set values in the same way and the original structure also gets updated:

d_j.j().pos().set([4,5,6]) -> {'0': 4, '1': 5,'2': 6}
print(d_j)             -> {'j.0': {'pos': 4, 'vel':2, 'acc':3}, 'j.1': {'pos': 5, 'vel':2, 'acc':3},'j.2': {'pos': 6, 'vel':2, 'acc':3}}

2D array to Nested DefDict

You can set nested DefDict values at a time as follows:

array_2d = [[11,12,13], [4,5,6]]
array_2d = [{'pos': 11, 'vel':12, 'acc':13}, {'pos': 4, 'vel':5, 'acc':6}]
array_2d = [np.array([11,12,13]), np.array([4,5,6])]
array_2d = np.array([[11,12,13],[4,5,6]])
d_j.set(array_2d)   ->  {'j.0': {'pos': 11, 'vel':12, 'acc':13}, 'j.1': {'pos': 4, 'vel':5, 'acc':6},'j.2': {'pos': 1, 'vel':2, 'acc':3}}

As long as both the top level and the sub-level are compatible with DefDict, any combinations should work. Top level DefDict calls the sub-level DefDict.set() internally.

Math Operation

DefDict is to support basic math operations for convenience, unlike dictionaries. Still, complex math should be done through such as numpy for efficiency. You can check #79 for the latest available math operations for DefDict

Not available for nested DefDict yet.

pos = DefDict(dict(x=0,y=0,z=0))
another_pos = pos.clone().set([1,1,1])
pos + another_pos -> {'x': 1, 'y': 1,'z': 1}

or

pos + [1,1,1] -> {'x': 1, 'y': 1,'z': 1}

or

pos + 1 -> {'x': 1, 'y': 1,'z': 1}
pos = DefDict(dict(x=1,y=2,z=3))
pos_rot = DefDict((dict(x=1,y=2,z=3),
                   dict(qx=0,qy=0,qz=0, qw=1))) # Tuple of two dicts
pos_rot += pos -> {'x': 2, 'y': 4,'z': 6, 'qx': 0,'qy': 0,'qz': 0, 'qw': 1}
pos += pos_rot -> {'x': 2, 'y': 4,'z': 6}

You can of course use other DefDict methods in combination

pos_rot.filter(pos) + 1 -> {'x': 2, 'y': 3,'z': 4, 'qx': 0,'qy': 0,'qz': 0, 'qw': 1}

Iterator

print(d_j)  -> {'j.0': {'pos': 4, 'vel':2, 'acc':3}, 'j.1': {'pos': 5, 'vel':2, 'acc':3},'j.2': {'pos': 6, 'vel':2, 'acc':3}}
for val in d_j: # or for val in d_j.value()
    print(val)
>> {'pos': 4, 'vel':2, 'acc':3}
>> {'pos': 5, 'vel':2, 'acc':3}
>> {'pos': 6, 'vel':2, 'acc':3}

You can use prefix/sufix

for val in d_j.pos():
    print(val)
>> 4
>> 5
>> 6
Clone this wiki locally