pandas column unique values count code example

Example 1: count unique pandas

df['column'].nunique()

Example 2: pandas count the number of unique values in a column

df['hID'].nunique()
5

Example 3: unique values in dataframe column count

df.groupby('mID').agg(['count', 'size', 'nunique']).stack()


             dID  hID  uID
mID                       
A   count      5    5    5
    size       5    5    5
    nunique    3    5    5
B   count      2    2    2
    size       2    2    2
    nunique    2    2    2
C   count      1    1    1
    size       1    1    1
    nunique    1    1    1

Example 4: dataframe python unique values rows

# get the unique values (rows)
df.drop_duplicates()