pandas value_counts applied to each column

Question

I have a dataframe with numerous columns (≈30) from an external source (csv file) but several of them have no value or always the same. Thus, I would to see qui

Answer 1

This is similar to @Jagie's reply but in addition:

1. Put zero for values absent in a column
2. Convert the counts to integer

    df = pd.DataFrame(
        data=[[34, 'null', 'mark'], [22, 'null', 'mark'], [34, 'null', 'mark']],     
        columns=["id", 'temp', 'name'], 
        index=[1, 2, 3]
    )
    result2 = df.apply(pd.value_counts).fillna(0).astype(int)