Efficient ways to iterate the dataset
It seems that selecting a subset of colums directly from the dataset, i.e., dataset["column"], is slow.
For a large dataset that does not fits the memory, how can I select only a subset of features from each example?

If I iterate over the dataset and then select the subset of features one by one, the resulted memory usage will be huge. Any ways to solve this?

Thanks
Efficient ways to iterate the dataset 
 For a large dataset that does not fits the memory, how can I select only a subset of features from each example?

If I iterate over the dataset and then select the subset of features one by one, the resulted memory usage will be huge. Any ways to solve this?

Thanks 
 It seems that selecting a subset of colums directly from the dataset, i.e., dataset["column"], is slow.