CODEWITHSUNDEEP
pythonpandas
VZG
VZG

Reputation: 63

pandas find value counts of column

From a data frame I want to count how many rows have same value for each unique value in a column.

df = pd.DataFrame({'c':[1,1,2,2,3,3],'l1':['a','a','a','a','b','b'],'l3':['b','a','b','a','a','a'],'l4':[1,2,3,4,5,6]})
cols = ['c','l1']
out = (df.set_index(cols).assign(pair=df.groupby(cols)['l3']
         .agg(makePair)).reset_index()
         .reindex(df.columns.union(['pair'],sort=False),axis=1))
    out['l1'].value_counts

I got wiered results as

<bound method IndexOpsMixin.value_counts of 0    a
1    a
2    a
3    a
4    b
5    b
Name: l1, dtype: object>

I expect

a 3
b 2

And actual ask is to do the value count on 'pair' ie out['pair'].value_counts where the error was more complicated

enter image description here

Upvotes: 0

Views: 574

Answers (1)

Aven Desta
Aven Desta

Reputation: 2443

You can use value_counts()

df = pd.DataFrame({'c':[1,1,2,2,3,3],'l1':['a','a','a','a','b','b'],'l3':['b','a','b','a','a','a'],'l4':[1,2,3,4,5,6]})
df['l1'].value_counts() # l1 is your column name

enter image description here

But, its already answered here. Next time google before asking!

Upvotes: 2

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