In [2]:
import numpy as np
from matplotlib import pyplot as plt
In [13]:
%matplotlib inline

plt.rcParams['figure.figsize'] = 10, 10
In [14]:
data = np.array(
    ((1, 2, 1),
     (3, 3, 0),
     (0, 0, 4))
)
    
plt.imshow(
    data,
    interpolation='nearest', 
    aspect='auto',
    cmap='Reds',  # other colors: https://matplotlib.org/examples/color/colormaps_reference.html
    vmin=0,
    vmax=5,
)
plt.colorbar()
Out[14]:
<matplotlib.colorbar.Colorbar at 0x7f15b874af60>