Question

Say I have a matrix in a numpy array in Python

In [3]: my_matrix
Out[3]: 
array([[ 2.,  2.,  2.,  2.,  2.,  2.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,
         0.,  0.,  0.,  0.,  0.],
       [ 0.,  0.,  0.,  0.,  0.,  0.,  2.,  2.,  2.,  2.,  0.,  0.,  0.,
         0.,  0.,  0.,  0.,  0.],
       [ 0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  0.,  2.,  2.,  2.,
         2.,  2.,  2.,  2.,  2.]])

Is there a way to have Python/IPython print my array as:

[ 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2; 
  0 0 0 0 0 0 2 2 2 2 0 0 0 0 0 0 0 0; 
  0 0 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 ]

? (~ similar to the way MATLAB does it)

Also, I have noticed that IPython does not use the full width of my terminal when printing numpy arrays. Other functions do (e.g. pprint.pprint). How can I change that?

Answer 1

Use numpy.set_printoptions. For increasing the line width:

np.set_printoptions(linewidth=150)

Replace 150 by whatever you need. Now, to print as you asked (I guess it means without the decimal point):

print my_matrix.astype('i')

If you have floating point values you can also control the precision for printouts with the option precision:

np.set_printoptions(precision=3)