Pretty print a matrix in Python 3 with numpy

matprint.py

def matprint(mat, fmt="g"):
    col_maxes = [max([len(("{:"+fmt+"}").format(x)) for x in col]) for col in mat.T]
    for x in mat:
        for i, y in enumerate(x):
            print(("{:"+str(col_maxes[i])+fmt+"}").format(y), end="  ")
        print("")
  
# Try it!      
import numpy as np

a = np.eye(5)*5

a[0,1] = 230000000000
a[2,4] = 0.000005

matprint(a)

# 5  2.3e+11  0  0      0  
# 0        5  0  0      0  
# 0        0  5  0  5e-06  
# 0        0  0  5      0  
# 0        0  0  0      5  

Nice one!

Very useful for small arrays.

This topic might interest you. Over there I have tried to picture a pretty printing function for numpy and other people have suggested interesting prototypes as well.

Awesome

Works just as advertised, thanks!

Solid work, thanks so much.

Nice! 666! Thanks.