7
submitted 9 months ago by driving_crooner to c/python@programming.dev

Hi, When im working with some big dataframes and I need to create some columns based on functions. So i have some code like this

Def function(row): function

And then I run the function on the df as

df['new column'] = df.apply(function, axis=1)

But I do this with 10 or more columns/functions at time. I don't think this is efficient because each time a column is created it had to parce the entire data frame. There's a way to create all the columns at the same time while parsing the rows only once?

Thanks for any help.

you are viewing a single comment's thread
view the rest of the comments
[-] snakedrake@lemmy.world 6 points 9 months ago

Then change your function to operate across the dataframe and return a different dataframe?

You can add multiple columns at the same time or do a merge statement of some kind

this post was submitted on 11 Dec 2023
7 points (88.9% liked)

Python

6232 readers
12 users here now

Welcome to the Python community on the programming.dev Lemmy instance!

📅 Events

October 2023

November 2023

PastJuly 2023

August 2023

September 2023

🐍 Python project:
💓 Python Community:
✨ Python Ecosystem:
🌌 Fediverse
Communities
Projects
Feeds

founded 1 year ago
MODERATORS