Finding the most common element-CodePudding

I have managed to identify which element appears most often but then I'm struggling to store that value in a variable, or even all items in a dictionary.

gather_occurrences = ['CAT', 'BIRD', 'DOG', 'BIRD', 'DOG', 'CAT', 'BIRD', 'RAT']
unique_occurrences = set(gather_occurances)
unique_occurrences = {'CAT', 'DOG', 'BIRD', 'RAT'}

counting = 1

for x in unique_occurrences:
    count = gather_occurrences.count(x)
    each_item = { counting : {x : count }}
    counting  = 1
    all_data = []
    all_data.append(each_item)
    print(each_item)

print(all_data)

Output:

{1: {'CAT': 2}}
{2: {'BIRD': 3}}
{3: {'RAT': 1}}
{4: {'DOG': 2}}

[{4: {'DOG': 2}}]

Each time I run the code the all_data part e.g. [{4: {'DOG': 2}}] only contains 1 piece of data instead of a list or a dictionary.

I keep swapping lines of code in the for loop around I've tried .extend instead of .append but I never seem to be able to get the output I want.

CodePudding user response：

The problem is that you define the holding structure in the loop, so you keep overwriting it, you need to define it before. Also is seems useless to have a 2-level dict for each value

gather_occurances = ['CAT', 'BIRD', 'DOG', 'BIRD', 'DOG', 'CAT', 'BIRD', 'RAT']
unique_occrrences = set(gather_occurances)
all_data = []
for x in unique_occrrences:
    all_data.append({x: gather_occurances.count(x)})
print(all_data)
#  [{'CAT': 2}, {'BIRD': 3}, {'DOG': 2}, {'RAT': 1}]

Note built-in collections.Counter

from collections import Counter

c = Counter(gather_occurances)
print(c)          # {'BIRD': 3, 'CAT': 2, 'DOG': 2, 'RAT': 1}
print(c.items())  # [('CAT', 2), ('BIRD', 3), ('DOG', 2), ('RAT', 1)]

CodePudding user response：

You should move all_data = [] outside of the for loop. Your problem occurs because each time it loops, you reset all_data, and so only the last thing you added to it remains.