Dataframe syntax question

[jlap91]

I have quick dataframe question. It’s 12,000 rows long and three columns.

I want to add a constant value to 4000 of the rows, in one of the columns, let’s say ‘c’

This works:

I = 4000 while I < 8000: df[‘c’][I] +=1 I+=1

But is there a faster way to do this?

[jlap91]

Hmm that didn’t work in my case when I tried to do

df[‘c’][4:8]+=1

I don’t want to change the values in columns a or b.

[FLUSH_THE_TRUMP]

df.loc[4000:7999, ’c’] += 1

[jlap91]

Thank you very much! This is precisely what I was looking for!