Merge row data of python data frame based on some condition

Question

I have a python data from as below. in every row I have some similar "string", in every round of similar string, I want to merge the first one with the first, then the first one with second one, then the first one with the third, can anyone help me please?

   row   label
1  x     a
2  x     bb
3  x     cc
4  x     rr
5  x     uu
6  y     ff
7  y     bb
8  y     nn

I want :

0  x  a
1  x  abb
2  x  acc
3  x  arr
4  x  auu
5  y  ff 
6  y  ffbb
7  y  ffnn

Rob Raymond · Accepted Answer · 2021-02-19 19:19:51Z

3

your transform is append first item in series to all other item in series
this is use of transform() with a lambda that does a list comprehension

df = pd.read_csv(io.StringIO("""   row   label
1  x     a
2  x     bb
3  x     cc
4  x     rr
5  x     uu
6  y     ff
7  y     bb
8  y     nn"""), sep="\s+")

df["label"] = df.groupby("row")["label"].transform(lambda s: [s.values[0]+x if i>0 else x for i,x in enumerate(s)])

	row	label
1	x	a
2	x	abb
3	x	acc
4	x	arr
5	x	auu
6	y	ff
7	y	ffbb
8	y	ffnn

answered Feb 19, 2021 at 19:19

Rob Raymond

31.5k3 gold badges19 silver badges34 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Merge row data of python data frame based on some condition

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related