pandas count unique values in column

1#TO count repetition of each unique values(to find How many times the same-
2# unique value is appearing in the data)
3
4item_counts = df["Your_Column"].value_counts()
5#Returns Dictionary => {"Value_name" : number_of_appearences} 

1df['column'].nunique()

1df = df.groupby('domain')['ID'].nunique()
2
3print (df)
4domain
5'facebook.com'    1
6'google.com'      1
7'twitter.com'     2
8'vk.com'          3
9Name: ID, dtype: int64

1pd.value_counts(df.Account_Type)
2
3Gold        3
4Platinum    1
5Name: Account_Type, dtype: int64

1df.groupby('mID').agg(['count', 'size', 'nunique']).stack()
2
3
4             dID  hID  uID
5mID                       
6A   count      5    5    5
7    size       5    5    5
8    nunique    3    5    5
9B   count      2    2    2
10    size       2    2    2
11    nunique    2    2    2
12C   count      1    1    1
13    size       1    1    1
14    nunique    1    1    1

1df.nunique()