How to open my files in data_folder with pandas using relative path?
Try
import pandas as pd
pd.read_csv("../data_folder/data.csv")
Pandas will start looking from where your current python file is located. Therefore you can move from your current directory to where your data is located with '..' For example:
pd.read_csv('../../../data_folder/data.csv')
Will go 3 levels up and then into a data_folder (assuming it's there) Or
pd.read_csv('data_folder/data.csv')
assuming your data_folder is in the same directory as your .py file.