python二维图制作的实例代码

import re
import csv
import matplotlib.pyplot as plt


x=[]
y=[]
m=eval(input())  #输入折线条数
for i in range(m):
 y.append([])
fo = open("E:\shu\2.txt", "r", encoding="UTF-8")  
plt.ylim(0, 20)      # 设定y轴范围
for line in fo.readlines(): # 按行输入
 line=line.split("
")[0] #分割
 if line !="": 判定是否为空
  don=line.split(" ")
  x.append(don[0])
  for i in range(len(don)-1):  
   y[i].append(eval(don[i+1]))



figsize = 12,8
plt.subplots(figsize=figsize)        # 设定整张图片大小
plt.grid(True)  # 是否网格化
markes = ["-o", "-s", "-^", "-p", "-^", "-v", "-p", "-d", "-h", "-2", "-8", "-6"]
plt.ylabel("Trade account unit: billion US dollars") #坐标命名
plt.xlabel("time") #坐标命名
for i in range(m):
 plt.plot(x, y[i],markes[i%12])
plt.legend(["America","china"],loc="upper left")
plt.savefig("Trade account.jpg", dpi=600) #保存图片
plt.show()