python绘制趋势图的示例

 import matplotlib.pyplot as plt #plt用于显示图片 import matplotlib.image as mping #mping用于读取图片 import datetime as dt import matplotlib.dates as mdates from pylab import * def draw_trend_chart(dates,y): mpl.rcParams['font.sans-serif'] = ['SimHei'] #指定默认字体 mpl.rcParams['axes.unicode_minus'] = False #解决保存图像是负号'-'显示为方块的问题 x = [dt.datetime.strptime(d,'%Y/%m/%d').date() for d in dates] #plt.figure(figsize=(8,8)) plt.figure() #plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%m/%d/%Y')) #plt.gca().xaxis.set_major_locator(mdates.DayLocator()) #plt.plot(x,y,"r--",linewidth=2) plt.plot(x,y,"r",linewidth=1) #plt.gcf().autofmt_xdate() #plt.xlabel("DATE") #x轴标签 plt.ylabel("WEIGHT") #y轴标签 plt.title("MY HEALTH TRACKING")#标题 plt.savefig("liuyang.png-600") #保存图片名称 lena = mping.imread('liuyang.png-600') #读取图片文件信息 lena.shape #（512,512,3） plt.imshow(lena) #显示图片 plt.axis('off') #不显示坐标轴 plt.title("") plt.show() #显示 def get_weight_data(filename): time = [] weight = [] fileContent=open(filename,"r") for eachline in fileContent: eachData = eachline.strip('\n').split(",") if eachData[-1].strip() =='': continue else: time.append(eachData[0]) weight.append(eachData[1]) return [time, weight] data = get_weight_data("data.csv") draw_trend_chart(data[0],data[1])