陌子曦的专栏

1.一.已经字符串 s = "i,am,lilei",请用两种办法取出之间的“am”字符。s = "my,name,is,zhangsan"print (s[3:7]) #方法一c = s.split(',')[1] #方法二print (c)二.在python中，如何修改字符串？答案：可以用字符串的replace方法.a = 'my name is lisi'a = a.rep...

一.求线性方程的斜率①最小二乘法import numpy as npfrom numpy.linalg import inv #逆矩阵from numpy import dot #矩阵乘from numpy import mat #矩阵#y=2x 求线性方程的斜率X = mat([1, 2, 3]).reshape(3, 1) #reshape 的作用就是修改矩阵的维度print(...

一、下载python源码包打开ubuntu下的shell终端，通过wget命令下载python源码包，如下图所示:wget https://www.python.org/ftp/python/3.5.0/Python-3.5.0rc3.tgz二、python的解压  tar zxvf Python-3.5.0rc3.tgz 三、python的编译与安装在对python进行编译之前，必须对它进行配置...

代码如下import matplotlib.pyplot as pltimport numpy as npx = np.linspace(-3, 3, 50)y1 = 2*x+1y2 = x**2plt.figure(num=3, figsize=(8, 5))plt.plot(x, y1, color="red", linewidth=1.0, linestyle='--') #画...