Python: Error when loading file into numpy array

Question

I have a file that looks like this, it has around 80,000 lines:

-1.1361818e-001  4.1730759e-002 -9.8787775e-001  9.7195663e-002
-1.1361818e-001  4.1730759e-002 -9.8787775e-001  9.7195663e-002
-1.1361818e-001  4.1730759e-002 -9.8787775e-001  9.7195663e-002
-1.1361818e-001  4.1730759e-002 -9.8787775e-001  9.7195663e-002

I'd like to work with numpy and scikit, and would like to write the file into an array so that it looks like this:

array = [[-1.1361818e-001,4.1730759e-002,-9.8787775e-001,9.7195663e-002],[-1.1361818e-001 ,4.1730759e-002,-9.8787775e-001,9.7195663e-002]...]

I found the following example at https://stackoverflow.com/a/10938021/1372560

I tried to adapt it to my example:

import numpy as np
a = np.loadtxt("/path2file", delimiter="\t")
print a

And I get the error "ValueError: invalid literal for float(): -1.1361818e-001 4.1730759e-002 -9.8787775e-001 9.7195663e-002"

I'm really stuck here and appreciate your help. Thanks a lot in advance!

Answer 1

That works for me :

import numpy as np
a = np.loadtxt("a.txt")
print a

Output:

[[-0.11361818  0.04173076 -0.98787775  0.09719566]
 [-0.11361818  0.04173076 -0.98787775  0.09719566]
 [-0.11361818  0.04173076 -0.98787775  0.09719566]
 [-0.11361818  0.04173076 -0.98787775  0.09719566]]

Answer 2

Simply leave the delimiter field empty, then it'll split at any whitespace. \t is a whitespace character only.:

Demo:

>>> import numpy as np
>>> from StringIO import StringIO                                                     
>>> c = StringIO("1.234\t1.23456  1.234234")                                                 
>>> np.loadtxt(c)                                                                           
array([ 1.234   ,  1.23456 ,  1.234234])

From docs:

delimiter : str, optional
    The string used to separate values. By default, this is any whitespace.