CODEWITHSUNDEEP
pythonpandasdataframe
Jgallagher
Jgallagher

Reputation: 111

Sorting a dataframe by month and grouping by a count

I have a Tags dataframe that has 2 columns "Date" & "Tag", there is multiple same dates and multiple of the same tag. I need to sort the table so that it shows a unique date alongside a unique tag and the count of how many times that tag occurred that month. Any ideas how I could do this? Please see below a screenshot of the current table.

Tags Table

Upvotes: 0

Views: 187

Answers (1)

quant
quant

Reputation: 4482

import pandas as pd
df = pd.DataFrame({'Date': ['Nov','Nov','Dec'],
                   'Name':[1,2,1]}) # sample dataframe

If you want to have the count of the unique Names by Date you can do this

df.groupby('Date')['Name'].nunique()
    Date
Dec    1
Nov    2

If you want to add this information as a new column in your dataframe you can do this

df['count'] = df.groupby('Date')['Name'].transform('nunique')
      Date  Name  count
0  Nov     1      2
1  Nov     2      2
2  Dec     1      1

Upvotes: 1

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