CODEWITHSUNDEEP
pythonpandascountcumulative-frequency
Feyzi Bagirov
Feyzi Bagirov

Reputation: 1372

Counting frequencies of the corresponding values in pandas [python 3]

I have the dataset with the following values: 

var1  var2 
1234  abc
2345  bcs
5678  csd
1234  abc
1234  bcs
5678  csd
1234  bcs
1234  xyz
1234  abc
9101  zzz

I need for every unique value in column var1 to count and show the top 3 frequency counts of the corresponding values in var2, and get the output, for example: 

var1  var2  count
1234  abc   3
1234  bcs   2
1234  xyz   1
5678  csd   2
9101  zzz   1

What's the most efficient way of doing that?

Upvotes: 2

Views: 104

Answers (3)

piRSquared
piRSquared

Reputation: 294218

You need to include nlargest

df.groupby('var1').var2.apply(lambda x: x.value_counts().nlargest(3)) \
    .reset_index(name='count').rename(columns={'level_1': 'var2'})

   var1 var2  count
0  1234  abc      3
1  1234  bcs      2
2  1234  xyz      1
3  2345  bcs      1
4  5678  csd      2
5  9101  zzz      1

Upvotes: 2

Feyzi Bagirov
Feyzi Bagirov

Reputation: 1372

This worked: 

df.groupby(['var1','var2']).count()

Upvotes: 0

Scott Boston
Scott Boston

Reputation: 153460

df_a.groupby(['var1','var2'])['var2'].agg({'count':'count'}).reset_index()

Upvotes: 1

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