How to add or increment single item of the Python Counter class

Question

A set uses .update to add multiple items, and .add to add a single one.

Why doesn\'t collections.Counter work the same way?

Answer 1

>>> c = collections.Counter(a=23, b=-9)

You can add a new element and set its value like this:

>>> c['d'] = 8
>>> c
Counter({'a': 23, 'd': 8, 'b': -9})

Increment:

>>> c['d'] += 1
>>> c
Counter({'a': 23, 'd': 9, 'b': -9} 

Note though that c['b'] = 0 does not delete:

>>> c['b'] = 0
>>> c
Counter({'a': 23, 'd': 9, 'b': 0})

To delete use del:

>>> del c['b']
>>> c
Counter({'a': 23, 'd': 9})

Counter is a dict subclass