count of the multiple values in a python dictionary

Question

I have a dictionary like the one below and I want to find out how many of the values in it are from the value entered by the user.

{'a': ['Sun', 'Jack'], 'b': ['John', 'Sun', 'Sarah'],...

Count how many 'Sun' in dictionary

Expected output: 2

Asked By: poe41

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Source

Answer 1

You can use sum.

dct = {'a': ['Sun'], 'b': ['John', 'Sun', 'Sarah']}
res = sum('Sun' in lst for lst in dct.values())
print(res)
# 2

Answered By: I'mahdi

Answer 2

I think the most straightforward way is to go through each value of the dict

dictionary = {'a': ['Sun', 'Jack'], 'b': ['John', 'Sun', 'Sarah']}
count = 0
for key in dictionary:
  if 'Sun' in dictionary[key]:
    count += 1
print(count)

Answered By: MMZK1526

Answer 3

Chain the all values of the dictionary with itertools.chain.from_iterable, and then count with collections.Counter:

>>> from collections import Counter
>>> from itertools import chain
>>> mapping = {'a': ['Sun', 'Jack'], 'b': ['John', 'Sun', 'Sarah']}
>>> Counter(chain.from_iterable(mapping.values()))['Sun']
2

Update:

For the new question you posted in the comment section:

>>> mp1 = {'a'：['Sun']，'b'：['John'，'Sun'，'Sarah']}
>>> mp2 = {'a'：100，'b'：80，'c'：90 }
>>> keys = (k for k, v in mp1.items() if 'Sun' in v)
>>> max_key = max(keys, key=mp2.__getitem__)
>>> max_key, mp2[max_key]
('a', 100)

Answered By: Mechanic Pig

Answer 4

one can also use enumerate for counting.

d = {'a': ['Sun', 'Jack'], 'b': ['John', 'Sun', 'Sarah']}

max([i for i, l in enumerate(d.values(), 1) if "Sun" in l])
2

d1 = {‘a’: [‘Sun’], ‘b’: [‘John’, ‘Sun’, ‘Sarah’]}

d2 = {‘a’: 100, ‘b’: 80, ‘c’: 90 }

def max_val(key_w, d1, d2):
    # prepare d2 for merging, by putting value numbers into lists
    d2 = { k: [v] for k,v in d2.items()}

    # merge the 2 dictionaries
    d1_d2 = { key:d1.get(key,[])+d2.get(key,[]) for key in set(list(d1.keys())+list(d2.keys())) }

    return sorted([(k, x.pop()) for k, x in list(d1_d2.items()) if key_w in x], key=lambda x: x[1]).pop()

max_val('Sun', d1, d2)

('a', 100)

Answered By: LetzerWille

count of the multiple values in a python dictionary

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