利用python的第三方包Pygal制作简单的折线图。
申明：本文仅供学习交流使用。源码大部分来自《python编程从入门到实践》；如有侵权，请联系我删除。
1 #!usr/bin/env python3 2 # -*-coding=utf-8 -*- 3 ''' 4 制作一个简单的交易走势图。源码大部分来自<python编程从入门到实践> 5 过程分析: 6 1,从网站下载数据并存储到本地，两种方法: 7 a,urlopen 8 b,requests 9 2,读取本地数据，利用pygal制作交易走势图 10 ''' 11 #正文开始 12 from __future__ import (absolute_import, division, print_function, unicode_literals) 13 try: 14 from urllib2 import urlopen 15 except ImportError: 16 from urllib.request import urlopen 17 import json 18 import requests 19 import pygal 20 from pygal.style import LightColorizedStyle as LCS,LightenStyle as LS 21 22 #第一种方法利用urlopen提取网络上存储的数据 23 #定义要提取数据的url 24 URL = "https://www.xxx.com/btc_close_2017.json" 25 read_url = urlopen(URL) #读取URL 26 read_response = read_url.read() #读取返回的数据 27 28 #开始存储数据到本地, 以'wb'形式(二进制) 29 with open('btc_close_2017_urllib.json', 'wb') as file_object: 30 file_object.write(read_response) #将读取到的数据写入到文件 31 32 file_urllib = json.loads(read_response) 33 print(file_urllib) 34 35 #第二种方法利用requests提取网络上存储的数据 36 #定义要提取数据的URL 37 URL = "https://www.xxx.com/btc_close_2017.json" 38 response = requests.get(URL) #利用requests读取URL并获取数据 39 40 #开始存储数据到本地文件; 41 with open('btc_close_2017_requests.json', 'w') as file_object: 42 file_object.write(response.text) #写入数据到本地文件，要以str格式写入 43 44 file_requests = response.json() 45 print(file_requests) 46 47 print("-----------------------I am delimiter-----------------") 48 #打印一下两种方法是不是获取到相同的数据 49 print(file_urllib == file_requests) #True 50 51 #开始读取相关数据 52 filename = 'btc_close_2017.json'; #加载文件 53 54 #以读的方式打开文件 55 with open(filename) as file_object: 56 btc_data = json.load(file_object) #将读取到的数据加载为json格式 57 58 print(btc_data) #打印是否符合预期 59 60 #打印每一天的信息,并将字符串转换成数值型的: 61 for btc_dict in btc_data: 62 date = btc_dict['date'] 63 month = int(btc_dict['month']) 64 week = int(btc_dict['week']) 65 weekday = btc_dict['weekday'] 66 close_price = int(float(btc_dict['close'])) #先将字符串转换为浮点型,再将浮点型转换成整型 67 print("{} is month: {}, week: {}, weekday: {}, the close price is: {}".format(date,month,week,weekday,close_price)) 68 69 70 #可视化,开始绘制收盘价折线图 71 72 #定义空列表以存储循环得到的项 73 dates, months, weeks, weekdays, close_prices = [], [], [], [], [] 74 #循环读取btc_data里的每一项 75 for btc_dict in btc_data: 76 date = btc_dict['date'] 77 month = int(btc_dict['month']) 78 week = int(btc_dict['week']) 79 weekday = btc_dict['weekday'] 80 close_price = int(float(btc_dict['close'])) #先将字符串转换为浮点型,再将浮点型转换成整型 81 82 #将每一项追加到对应的空列表 83 dates.append(date) 84 months.append(month) 85 weeks.append(week) 86 weekdays.append(weekday) 87 close_prices.append(close_price) 88 89 line_chart = pygal.Line(x_label_rotation=20,show_minor_x_labels=False) #x轴标签顺时针旋转20度,show_minor_x_labels告诉pygal不必显示全部的x轴标签 90 line_chart.title = "Close Price ($)" #标题 91 line_chart.x_title = "Dates" #x轴标题 92 line_chart.y_title = "Price" #y轴标题 93 line_chart.x_labels = dates #x轴标签 94 line_chart.x_labels_major = dates[::20] #让x轴坐标每隔20天显示第一次; 95 line_chart.add("BTC", close_prices) # 96 line_chart.render_to_file('closeprice.svg') 97 98 ''' 99 写一些折线图的样式 100 ''' 101 my_style = LS("#999888",base_style=LCS) 102 my_config = pygal.Config() 103 my_config.x_label_rotation = 20 104 my_config.show_legend = False 105 my_config.show_minor_x_labels = False 106 my_config.title_font_size = 10 107 my_config.label_font_size = 10 108 my_config.major_label_font_size = 18 109 my_config.truncate_label = 10 110 my_config.show_y_guides = False 111 my_config.width = 1000 112 113 #利用样式可视化 114 line_chart = pygal.Line(my_config,style=my_style) 115 line_chart.title = "BTC close price in 2017" 116 line_chart.x_title = "Dates" 117 line_chart.y_title = "Price" 118 line_chart.x_labels = dates 119 line_chart.x_labels_major = dates[::20] 120 line_chart.add("SPJ",close_prices) 121 line_chart.render_to_file("closeprice1.svg")