pandas count occurrences of unique values in column including nulls code example

Example 1: how to count number of unique values in a column python

pd.value_counts(df.Account_Type)

Gold        3
Platinum    1
Name: Account_Type, dtype: int64

Example 2: values of unique from dataframe with count

data = df.groupby('ColumnName')['IDColumnName'].nunique()
print(data)