count the frequency that a value occurs in a dataframe column

Question

I have a dataset

|category|
cat a
cat b
cat a

I\'d like to be able to return something like (showing unique values and frequency)

Answer 1

If you want to apply to all columns you can use:

df.apply(pd.value_counts)

This will apply a column based aggregation function (in this case value_counts) to each of the columns.