For input file separate by space/tab like:
1 2 3 4 5 6 7 8 9 How to read the line and split the integers, then save into either lists or tuples? Thanks.
data = [[1,2,3], [4,5,6], [7,8,9]] data = [(1,2,3), (4,5,6), (7,8,9)] 
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5 Answers
One way to do this, assuming the sublists are on separate lines:
with open("filename.txt", 'r') as f: data = [map(int, line.split()) for line in f] Note that the with statement didn't become official until Python 2.6. If you are using an earlier version, you'll need to do
from __future__ import with_statement 
1 Comment
David Z
+1 this is closest to the way I'd do it, and I think the best example of "best practices" (whatever that means) of the 5 answers here.
If you find yourself dealing with matrices or tables of numbers, may I suggest numpy package?
import numpy as np data = np.loadtxt(input_filename) 
Comments
tuples = [tuple(int(s) for s in line.split()) for line in open("file.txt").readlines()]
I like Jeff's map(int, line.split()), instead of the inner generator.
5 Comments
Stan
Does this way really store a splited line into a tuple? Can you please explain a bit more? Thanks.
David Z
Actually this will give you a list of lists, not a list of tuples (because
str.split returns a list). Basically what it does is open the file, read in its lines, then iterate through them (for tup in ...) and split each one on whitespace.Stan
So how to store in a tuple? That is part of my original question. Thanks.
Stephen
@David : the OP said lists or tuples, but good call, thanks, edited. @Stan : just construct a tuple from the list.
David Z
@Stephen: yep, my comment was directed to Stan's comment above mine, not so much at your answer. Sorry for not making that clear.
You mean, like this?
update
Just convert each string into int
string = """1 2 3 4 5 6 7 8 9""" data = [] for line in string.split("\n"): #split by new line data.append( map( int, line.split(" ") ) ) # split by spaces and add print( data ) Output:
[['1', '2', '3'], ['4', '5', '6'], ['7', '8', '9']]
[[1, 2, 3], [4, 5, 6], [7, 8, 9]] Da daaaa!!!
def getInts(ln): return [int(word) for word in ln.split()] f = open('myfile.dat') dat = [getInts(ln) for ln in f] 