What is the difference in importing csv file with reader and with .read
import csv
f = open("nfl.csv", 'r')
data = csv.reader(f)
and using read directly
f = open('nfl.csv', 'r')
data = f.read()
1 Answer
From the docs, the reader will
Return a reader object which will iterate over lines in the given csvfile.
whereas the read on a file, will
reads some quantity of data and returns it as a string. size is an optional numeric argument. When size is omitted or negative, the entire contents of the file will be read and returned; it’s your problem if the file is twice as large as your machine’s memory.
So, the first way, you can use
for row in reader:
and processes the lines one at a time. You can also do things one line at a time for a file in general.
The csv module expects comma seprated columns though, so you get a list or a dictionary of the data depending on how you set things up.
f.read()just reads a file and has no concept of CSV.data = csv.reader(f)assigns the reader object to the namedata, but does not consume it, compared to for exampledata = list(csv.reader(f)).