How to append arrays within a class

[shaynehansen]

Essentially the class will act as a dictionary.

I need to append the string 'Time' to the self._keys list.
Also, I have a (32768, 1233) self._arr. I want to append a (32768, ) self._time to the self._arr. Such that the self._arr will become (32768, 1234).

class NFACDictionary(collections.abc.Mapping):
   
    def __init__(self, ecfgFilename, eudFilename, timeFilename):
        keys = self._key_data(ecfgFilename)
        array = self._read_data(eudFilename)
        time = self._read_time_data(timeFilename)
        #append 'Time' to self._keys.  Append time values to self._arr. <---- This is what I'm trying to do.
        self._keys = keys
        self._arr = array
        self._time = time

[nilamo]

Are self ._keys/._arr/._time lists? Just use .append().

[shaynehansen]

_keys is a list.

_arr and _time are numpy arrays.

[ichabod801]

You might want to look at collections.UserDict. A subclass of that should be easier to implement. The collections.abc classes are usually used for testing classes. To do it the way you're doing it, you also need to implement all of the abstract methods. And keys is a method of Mapping, but it looks like you're replacing it with a list.