Loading data for Machine learning

Question

I have a dataset with >100,000 data points. I am creating ML model and plots for subset of data every time when it meets certain condition.

Will it be better if i load the data before for loop. Or, load the data every time inside for loop.

In first case it will take less time to run "for loop" because i am not loading the data every time, but memory is allocated for all data entire time.

data = pd.read_csv("sample.csv")
data.drop(['column2', 'column3']

for i in range(0,10):
    data['column1'] == i
    # performing the machine learning model and plots

In second case i will be loading the dataset every time but only subset of data will be remaining in the memory after i drop columns and subset the data.

for i in range(0,10):
    data = pd.read_csv("sample.csv")
    data.drop(['column2', 'column3']
    data['column1'] == i

Which is a better approach?

I have tried both, but want to know which is correct.

Answer 1

I think in 1st approach: you will insert the data once and it will loops according to the condition.

But in 2nd approach: for each loop it has to loads and drop certain columns of your data which will take a lot of time.

My suggestion is to go with the 1st approach because the run time less and it is the correct way to approach.

Hope it helps your question.