[Python] Get rows with unique value in a specific column in pandas

Following is my data frame.


id name class
--------------------------
0 Nick a
1 Jane b
2 Jacon a
3 Jack b
4 Cooze a
--------------------------
5 Nick b
6 Jane b
7 Jacon c
8 Jack a
9 Cooze a


I need to get all names that have unique value in class column, i.e.:

id name class count
-----------------------------------
0 Jane b 2
1 Cooze a 2


What I have done:

data = {'name':['Nick', 'Jane', 'Jacon', 'Jack', 'Cooze', 'Nick', 'Jane', 'Jacon', 'Jack', 'Cooze'],
'class':['a', 'b', 'a', 'b', 'a', 'b', 'b', 'c', 'a', 'a']}

df = pd.DataFrame(data)
new_data = df.groupby('name')['class'].unique()
print(new_data)


What I get is:

name
Jacon [a]
Jane [a, b]
jack [b, a]
krish [a, c]
nick
Name: class, dtype: object



In next step I have to get the length of objects in column class, and return the ones that are 1. But first I get different errors when I try to get the length of objects in the second column and second, I have the feeling it must be easier than this! I am very beginner in pandas, does anyone know how can I get it? Thank you in advance.

Continue reading...