用python绘制趋势图

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") #保存图片名称

    lena = mping.imread('liuyang.png')  #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('
').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])