Counting keys in dictionary of dictionary in python

Question

I have dict sample:

dictsample which have this structure dictsample.update({key: dif_k}), and dif_k have this structure dif_k.update({k:v})

dictsample:

{Object1 : { size : 14, cell: G, capacity : 35}, Object2 : { size : 14, load : 2}, Object3 : { size : 12, cell : F, load : 3, throughput : 55}, ...}

I need output like this:

{Object1 : 3, Object2 : 2, Object3 : 4, ...}

Code I have tried:

ct = {}
for key, dif_k in dictsample.iteritems():
    for k, v in dif_k.iteritems():
        dictcounter = k.count(k)
        ct.update({key:dictcounter})

And all I got is: {Object1 : 1, Object2 : 1, Object3 : 1, ...}

wim · Accepted Answer · 2017-03-28 21:29:58Z

3

Try something like this dict comprehension instead:

{k: len(v) for k,v in dictsample.iteritems()}

edited Mar 28, 2017 at 21:29

answered Mar 28, 2017 at 21:29

wim

369k114 gold badges682 silver badges821 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

jovicbg Over a year ago

This works great, but I got a problem when trying to transform to dataframe: If using all scalar values, you must pass an index I wanna df with just first columns with keys and second with counted values.

Ajax1234 · Accepted Answer · 2017-03-28 22:33:11Z

1

You can also do this:

the_list = {i:len(dictsample[i]) for i in dictsample.keys()}

this method does not require iteritems and is shorter.

Edit:

To access the values by a numerical element, try this:

the_list = {len(dictsample[i]):i for i in dictsample.keys()}

edited Mar 28, 2017 at 22:33

answered Mar 28, 2017 at 21:58

Ajax1234

71.7k9 gold badges67 silver badges110 bronze badges

2 Comments

jovicbg Over a year ago

Thanks, but after that I have same problem with creating dataframe in pandas: If using all scalar values, you must pass an index I commented above... what do I need to put as an index? @Ajax1234

Ajax1234 Over a year ago

if you need a numerical index in the dictionary, just switch the dictionary key and values. Please see my recent edit.

mic4ael · Accepted Answer · 2017-03-28 21:33:40Z

1

Can't you do it a bit simpler. Wouldn't something like this do the trick?

ct = {}
for key in dictsample:
    ct[key] = len(dictsample[key])

edited Mar 28, 2017 at 21:33

answered Mar 28, 2017 at 21:28

mic4ael

8,4304 gold badges32 silver badges44 bronze badges

2 Comments

Chris Over a year ago

You don't need dif_k.keys(). Python already iterates over dictionaries by key by default. So dif_k is sufficient.

jovicbg Over a year ago

This works great too, as an answer above, but I got the same problem.

Collectives™ on Stack Overflow

Counting keys in dictionary of dictionary in python

3 Answers 3

1 Comment

2 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

2 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related