示例简要说明：
利用matplotlib绘制直方图，数据标签也要进行相关绘制。
from matplotlib import pyplot as plt
import numpy as np
x = np.random.normal(2,12,10000)
print(x.min(),x.max())
num_section = (x.max()-x.min())/10
y = [x.min() + num_section*i for i in range(11)]
# print(y)
# print(np.array(y))
# for i in range(11):
# print(x.min() + num_section*i)
# print(x)
# plt.plot(x)
# plt.bar(y,x)
# plt.xticks(y,rotation=45)
# plt.ylim([1,100])
# plt.yticks([j for j in range(1,100,4)])
n1,bins1,patch = plt.hist(x,bins=10,rwidth=0.5)
print(patch,n1,bins1)
print(len(bins1))
x_mean = [(bins1[j] + bins1[j+1])/2 for j in range(len(bins1)-1)]
for a,b in zip(x_mean,n1):
plt.text(a-1,b+2,b)
# plt.text(-20,35,'nice day')
plt.scatter(x_mean,n1)
print(x_mean)
# plt.plot(x)
plt.show()
