matplotlib图例标签在键下？

Question

How to adjust label location relate to key?I reclassified the data and displayed a discrete corbar which looks like multi-handles legend. Actually ,I couldn't find any parameters about the location of labels(text or numbers).The default setting is keys in left while label in right. Could I change the position? such as labels under keys or above. My purpose is to show the legend as follows (label under key and no space between keys:

import matplotlib.patches as mpatches
import matplotlib.pyplot as plt
import numpy as np

data  = np.random.randint(8, size=(100,100))
cmap = plt.cm.get_cmap('PiYG', 8) 
plt.pcolormesh(data,cmap = cmap,alpha = 0.75)
# Set borders in the interval [0, 1]
bound = np.linspace(0, 1, 9)
# Preparing borders for the legend
bound_prep = np.round(bound * 7, 2)
# Creating 8 Patch instances
plt.legend([mpatches.Patch(color=cmap(b)) for b in bound[:-1]],
       ['{}'.format(bound_prep[i]) for i in range(8)],
       bbox_to_anchor=(0,-0.25,1,0.2),ncol=len(bound))

It seems that there is no parameters to adjust location of labels.

Answer 1

import matplotlib.pyplot as plt
import numpy as np

data  = np.random.randint(8, size=(100,100))
cmap = plt.cm.get_cmap('PiYG', 8)
fig, ax = plt.subplots()
pcm = ax.pcolormesh(data,cmap = cmap,alpha = 0.75, vmin=0, vmax=8)
fig.colorbar(pcm, ax=ax)
plt.show()