Pandas dataframe insert rows

Question

I got a problem dealing with dataframe. I want to insert rows in DF and modify its related values:

for example I have

time  value
0  10:00      2
1  11:00      4
2  12:00      6
3  13:00      8

and the ideal result should be:

time  value
0  10:00      1
1  11:00      2
0  10:00      1
1  11:00      2
2  12:00      6
3  13:00      8

Which duplicate first two rows and then divide its value evenly.

The code can only append rows but how to modify its values in a faster way? df[0:2].append(df[0:2]).append(df[2:])

Community · Accepted Answer · 2017-05-23 11:52:58Z

3

first_two = df[: 2]
first_two.value = first_two.value / 2

df = pd.concat([first_two, first_two, df[2:]])

Edit

as Paul H points out below, it's better touse iloc for this stuff.

CommunityBot

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answered May 28, 2015 at 22:25

Ami Tavory

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1 Comment

Better to use the .iloc attribute here. IOW: first_two = df.iloc[:2]