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)]
views:
126answers:
5
+4
A:
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
Jeff Bradberry
2010-06-25 23:55:37
+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.
David Zaslavsky
2010-06-26 00:30:49
+2
A:
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.
Stephen
2010-06-25 23:58:05
Does this way really store a splited line into a tuple? Can you please explain a bit more? Thanks.
Stan
2010-06-26 00:23:51
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.
David Zaslavsky
2010-06-26 00:29:41
@David : the OP said lists or tuples, but good call, thanks, edited. @Stan : just construct a tuple from the list.
Stephen
2010-06-26 01:04:05
@Stephen: yep, my comment was directed to Stan's comment above mine, not so much at your answer. Sorry for not making that clear.
David Zaslavsky
2010-06-26 01:49:50
+1
A:
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!!!
OscarRyz
2010-06-25 23:58:43
I end up using mapping function. Still didn't figure out another way to convert all read in string into a integer.
Stan
2010-06-26 00:11:24
+1
A:
def getInts(ln):
return [int(word) for word in ln.split()]
f = open('myfile.dat')
dat = [getInts(ln) for ln in f]
Hugh Bothwell
2010-06-26 00:24:00
+2
A:
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)
Dat Chu
2010-06-26 04:14:34