Question

Using Python’s csv module, is it possible to read an entire, large, csv file into a lazy list of lists?

I am asking this, because in Clojure there are csv parsing modules that will parse a large file and return a lazy sequence (a sequence of sequences). I’m just wondering if that’s possible in Python.

Answer 1

Unless I’m misunderstanding you, this is the default behavior, which is the very essence of reading through a csv file:

import csv

def lazy(csvfile):
    with open(csvfile) as f:
        r = csv.reader(f)
        for row in r:
            yield row

gives you back one row at a time.