Find average using dictionary key

Question

I have these columns in my dataframe:

I need to find average of all the [Count] values where Day is 1 or 2 and so on.

I've tried that by using key dictionary:

col_dict = dict(zip(df6.Day, df6.Count))

k=2  # Enter Day
#print(k)
for keys in col_dict.keys():
    if keys == k:
        for i in col_dict:
            a=col_dict[keys] where col_dict==k

But I think this code is not correct.

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Possible duplicate of [Python 3.4 - How to get the average of dictionary values?](https://stackoverflow.com/questions/30687244/python-3-4-how-to-get-the-average-of-dictionary-values) — Ramesh-X, Jun 28 '18 at 12:23

score 0 · Answer 1 · answered Jun 28 '18 at 11:29

Pandas has purpose-built methods for grouping and aggregating data. Here you can use groupby + mean:

res = df6.groupby('Day')['Count'].mean()

There is no need for dictionary conversion or explicit iteration when vectorised operations are available. If you need a dictionary result, you can convert in a separate step:

res_dict = res.to_dict()

Find average using dictionary key

1 Answers1