unique values in dataframe column count

df['hID'].nunique()
5

df['column'].nunique()

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

for col in df:
    print(df[col].unique())

#List unique values in the df['name'] column
df.name.unique()

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

df = df.groupby('domain')['ID'].nunique()

print (df)
domain
'facebook.com'    1
'google.com'      1
'twitter.com'     2
'vk.com'          3
Name: ID, dtype: int64

df.nunique()