Read first N lines using readlines

Question

My python code goes like this

with open('file.txt') as w:
    k = np.asarray(w.readlines(),np.float)

But when I do this k is an array with all lines read from file.txt

I am trying to figure to read only the first n lines and store k using np.asarray How to edit this code with n

Thanks for the help!

Warning `[:n]` won't work for large files (file must be copied into memory). The second method(s) are preferred — OneCricketeer, Nov 17 '16 at 06:53
New versions of `np.genfromtxt` take a `max_rows` parameter. — hpaulj, Nov 17 '16 at 13:30

score 2 · Accepted Answer · answered Nov 17 '16 at 06:52

2

from itertools import islice
with open("file.txt") as myfile:
    k = list(islice(myfile, n))
print k

or

with open('file.txt') as w:
    k = np.asarray(w.readlines(),np.float)
    k = k[:,n]

answered Nov 17 '16 at 06:52

Sunil B N

1 Answers1