Reading one integer at a time using python

Question

How can I read int from file? I have a large (512 MB) txt file that contains integer data like:

0 0 0 10 5 0 0 140
0 20 6 0 9 5 0 0

Now, if I use c = file.read(1), I get only one character at a time, but I need one integer at a time. How:

c = 0
c = 10
c = 5
c = 140 and so on...

Any big heart, please help. Thanks in advance.

+5

whoone Jul 19 '12 at 5:38

3 answers

512 . , :

my_int_list = [int(v) for v in open('myfile.txt').read().split()]

, , :

def my_ints(fname):
    for line in open(fname):
        for val in line.split():
            yield int(val)

:

for c in my_ints('myfile.txt'):
    # do something with c (which is the next int)

+2

thebjorn 19 . '12 6:05

I would do it like this:

-1

azhrei · Accepted Answer · 2012-07-19T05:45:36+0000

Here is one way:

with open('in.txt', 'r') as f:
  for line in f:
    for s in line.split(' '):
      num = int(s)
      print num

By performing for line in f, you read bit by bit (using neither read() all, nor readlines). Important because your file is large.

Then you break each line into spaces and read each number as you go.

You can make more mistakes than this simple example, which will be barf if the file contains corrupted data.

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