There was warning when I wrote the function mentioned in this video

Hi Nurian,
thanks for reaching out! What you're seeing is a warning, rather than an error. This means that your code is running, you're just receiving a warning.
The warning says you might want to allocate in a different way using the .loc. If you'd like to get a more detailed undersanding on the iloc and loc method from the pandas library, you can also check out our course on Data Cleaning and Preprocessing with pandas. Section 4 has a few lectures on indexing:
Data Cleaning and Preprocessing with pandas | 365 DataScience

Hope this helps!
Best,
The 365 Team