Group by list python

Groupby and list

In [1]: df = pd.DataFrame( {'a':['A','A','B','B','B','C'], 'b':[1,2,5,5,4,6]})
        df

Out[1]: 
   a  b
0  A  1
1  A  2
2  B  5
3  B  5
4  B  4
5  C  6

In [2]: df.groupby('a')['b'].apply(list)
Out[2]: 
a
A       [1, 2]
B    [5, 5, 4]
C          [6]
Name: b, dtype: object

In [3]: df1 = df.groupby('a')['b'].apply(list).reset_index(name='new')
        df1
Out[3]: 
   a        new
0  A     [1, 2]
1  B  [5, 5, 4]
2  C        [6]

Source: stackoverflow.com

Group by list python

values = set(map(lambda x:x[1], mylist))
newlist = [[y[0] for y in mylist if y[1]==x] for x in values]

Source: stackoverflow.com

Similar codes

0 vote243 views1 answer
Onehot encode list of columns pandas
Python
0 vote239 views3 answers
How to print a text in python
Python
3 votes250 views3 answers
How to get median mode average of a python list
Python
0 vote272 views1 answer
Return the indices of the bins
Python
25 votes309 views2 answers
Python if null
Python
11 votes260 views1 answer
Pandas xlsx to csv
Python
1 vote245 views1 answer
Insert data in django models
Python
1 vote236 views1 answer
Select realted for foreign key table in django
Python
54 votes239 views2 answers
How to run django requirement.txt
Python
1 vote232 views1 answer
List comprehension - list files with extension in a directory
Python