CODEWITHSUNDEEP
pythonnumpygenfromtxt
Darryl Sergison
Darryl Sergison

Reputation: 31

numpy genfromtxt columns

I am having what seems like a stupidly simple problem with numpy genfromtxt. This is a (very) simplified version of my code:

import numpy as np

in_file_1 = raw_input ('enter name of template file to be scaled:\n')
spec_1 = np.genfromtxt(in_file_1, delimiter = [8,24], dtype =float)
print spec_1

The file i am reading is totally simple, two columns no header etc:

6392.01   0.90286163
6392.05   0.88731778
6392.09   0.87789831
6392.13   0.87716535
6392.16   0.88523003
6392.20   0.90948176
6392.24   0.93056874
6392.28   0.95782283
6392.32   0.98056805
6392.36   0.99623797
6392.39   0.99458828
6392.43   0.9848269
6392.47   0.96011146
6392.51   0.92864767

When I read the above using genfromtxt on the python command line it gives me the two column array as i expect:

>>> import numpy as np
>>> in_file_1 = raw_input ('enter name of template file to be scaled:\n')
enter name of template file to be scaledl_1714650_052_no_head.txt
>>> spec_1 = np.genfromtxt(in_file_1, delimiter = [8,24], dtype =float)
>>> spec_1
array([[  6.39201000e+03,   9.02861630e-01],
       [  6.39205000e+03,   8.87317780e-01],
       [  6.39209000e+03,   8.77898310e-01],
       [  6.39213000e+03,   8.77165350e-01],
       [  6.39216000e+03,   8.85230030e-01],
       [  6.39220000e+03,   9.09481760e-01],
       [  6.39224000e+03,   9.30568740e-01],
       [  6.39228000e+03,   9.57822830e-01],
       [  6.39232000e+03,   9.80568050e-01],
       [  6.39236000e+03,   9.96237970e-01],
       [  6.39239000e+03,   9.94588280e-01],
       [  6.39243000e+03,   9.84826900e-01],
       [  6.39247000e+03,   9.60111460e-01],
       [  6.39251000e+03,   9.28647670e-01]])
>>>

But when i run it as the script (read_test.py) at the top of this post it returns a single column of strings:

[scrooge:Acc_cont_removal/All_stars/Test] darryl% python read_test.py 
enter name of template file to be scaled:
l_1714650_052_no_head.txt
[[  6.39201000e+03   9.02861630e-01]
 [  6.39205000e+03   8.87317780e-01]
 [  6.39209000e+03   8.77898310e-01]
 [  6.39213000e+03   8.77165350e-01]
 [  6.39216000e+03   8.85230030e-01]
 [  6.39220000e+03   9.09481760e-01]
 [  6.39224000e+03   9.30568740e-01]
 [  6.39228000e+03   9.57822830e-01]
 [  6.39232000e+03   9.80568050e-01]
 [  6.39236000e+03   9.96237970e-01]
 [  6.39239000e+03   9.94588280e-01]
 [  6.39243000e+03   9.84826900e-01]
 [  6.39247000e+03   9.60111460e-01]
 [  6.39251000e+03   9.28647670e-01]]
[scrooge:Acc_cont_removal/All_stars/Test] darryl%

I have tried various configurations of delimiters etc but I cannot figure out what is happening and this code worked fine a few days ago. Running on OSX (Lion) with python v2.7.

Any ideas gratefully received. Darryl

Upvotes: 3

Views: 4103

Answers (1)

Nolen Royalty
Nolen Royalty

Reputation: 18633

You are getting exactly the answer you should get!

>>> numpy.genfromtxt('testfile', delimiter=[8,24], dtype = float)
array([[  6.39201000e+03,   9.02861630e-01],
       [  6.39205000e+03,   8.87317780e-01],
       [  6.39209000e+03,   8.77898310e-01],
       [  6.39213000e+03,   8.77165350e-01],
       [  6.39216000e+03,   8.85230030e-01],
       [  6.39220000e+03,   9.09481760e-01],
       [  6.39224000e+03,   9.30568740e-01],
       [  6.39228000e+03,   9.57822830e-01],
       [  6.39232000e+03,   9.80568050e-01],
       [  6.39236000e+03,   9.96237970e-01],
       [  6.39239000e+03,   9.94588280e-01],
       [  6.39243000e+03,   9.84826900e-01],
       [  6.39247000e+03,   9.60111460e-01],
       [  6.39251000e+03,   9.28647670e-01]])
>>> print _
[[  6.39201000e+03   9.02861630e-01]
 [  6.39205000e+03   8.87317780e-01]
 [  6.39209000e+03   8.77898310e-01]
 [  6.39213000e+03   8.77165350e-01]
 [  6.39216000e+03   8.85230030e-01]
 [  6.39220000e+03   9.09481760e-01]
 [  6.39224000e+03   9.30568740e-01]
 [  6.39228000e+03   9.57822830e-01]
 [  6.39232000e+03   9.80568050e-01]
 [  6.39236000e+03   9.96237970e-01]
 [  6.39239000e+03   9.94588280e-01]
 [  6.39243000e+03   9.84826900e-01]
 [  6.39247000e+03   9.60111460e-01]
 [  6.39251000e+03   9.28647670e-01]]

It's just the difference between printing and getting the representation of the result.

>>> result = numpy.genfromtxt('testfile', delimiter=[8,24], dtype = float)
>>> repr(result)
'array([[  6.39201000e+03,   9.02861630e-01],\n       [  6.39205000e+03,   8.87317780e-01],\n       [  6.39209000e+03,   8.77898310e-01],\n       [  6.39213000e+03,   8.77165350e-01],\n       [  6.39216000e+03,
  8.85230030e-01],\n       [  6.39220000e+03,   9.09481760e-01],\n       [  6.39224000e+03,   9.30568740e-01],\n       [  6.39228000e+03,   9.57822830e-01],\n       [  6.39232000e+03,   9.80568050e-01],\n
[  6.39236000e+03,   9.96237970e-01],\n       [  6.39239000e+03,   9.94588280e-01],\n       [  6.39243000e+03,   9.84826900e-01],\n       [  6.39247000e+03,   9.60111460e-01],\n       [  6.39251000e+03,   9.2864
7670e-01]])'

>>> str(result)
'[[  6.39201000e+03   9.02861630e-01]\n [  6.39205000e+03   8.87317780e-01]\n [  6.39209000e+03   8.77898310e-01]\n [  6.39213000e+03   8.77165350e-01]\n [  6.39216000e+03   8.85230030e-01]\n [  6.39220000e+03
 9.09481760e-01]\n [  6.39224000e+03   9.30568740e-01]\n [  6.39228000e+03   9.57822830e-01]\n [  6.39232000e+03   9.80568050e-01]\n [  6.39236000e+03   9.96237970e-01]\n [  6.39239000e+03   9.94588280e-01]\n [
 6.39243000e+03   9.84826900e-01]\n [  6.39247000e+03   9.60111460e-01]\n [  6.39251000e+03   9.28647670e-01]]'

Notice how the str version doesn't have commas but the repr does?

Upvotes: 4

Related Questions