python 学习
numpy,matplotlib库
code:
import numpy as np
import matplotlib.pyplot as plt
x= np.arange(0,4*np.pi,0.02)
y=np.sin(x)
plt.plot(x,y)
plt.show()
字符串相加
a=‘1’ b=‘22’
a+b=‘122’
print("let'\s go")
let's go
print(r"let's\go")
let's\ go
字符串分片索引