《Python编程：从入门到实践》学习记录（16）项目-解析CSV与JSON；matplotlib, pygal绘图

import csv
from matplotlib import pyplot as plt
from datetime import datetime
def read_data_from_csv():
    """
    从CSV文件中读取日期/最高温/最低温数据
    :return:
    """
    # file_path = 'data/sitka_weather_07-2014.csv'
    file_path = 'data/sitka_weather_2014.csv'
    # file_path = 'data/death_valley_2014.csv'
    with open(file_path) as csv_file:
        csv_reader = csv.reader(csv_file)
        # enumerate(iterable)可用来获取每个元素的索引
        for index, item in enumerate(next(csv_reader)):
            print(index, item)
        # 日期
        dates = []
        # 用于保存每天的最高气温
        highs = []
        # 最低温
        lows = []
        for row in csv_reader:
            # 将字符串转换为指定格式的datetime
            dates.append(datetime.strptime(row[0], '%Y-%m-%d'))
            # 最最高温数据
            highs.append(int(row[1]))
            # 最低温数据
            lows.append(int(row[3]))
        return [dates, highs, lows]
def draw(data):
    """
    绘图
    :param data: 日期与温度
    :return:
    """
    plt.figure(dpi=128, figsize=(10, 6))
    # 绘制最高温
    plt.plot(data[0], data[1], c='red')
    # 绘制最低温
    plt.plot(data[0], data[2], c='blue')
    # 填充温度之间的区域
    plt.fill_between(data[0], data[1], data[2], facecolor='blue', alpha=0.1)
    plt.show()
draw(read_data_from_csv())

import json
import pygal
def read_json_data_from_file(file_path: str):
    """
    读取json文件数据
    :param file_path:
    :return:    解析的字典
    """
    date = "date"
    month = "month"
    week = "week"
    weekday = "weekday"
    close = "close"
    # 打开文件
    with open(file_path) as json_file:
        # 解析为json
        json_data = json.load(json_file)
        # 存储数据集
        dates, months, weeks, weekdays, closes = [], [], [], [], []
        # 遍历json数组
        for json_obj in json_data:
            # 每个json对象都是一个dict，取到json的每个属性值
            dates.append(json_obj[date])
            months.append(json_obj[month])
            weeks.append(json_obj[week])
            weekdays.append(json_obj[weekday])
            closes.append(float(json_obj[close]))
        return {"dates": dates, "months": months, "weeks": weeks, "weekdays": weekdays, "closes": closes}
def draw(data: dict):
    """绘图"""
    line_chart = pygal.Line(x_label_rotation=20, show_minor_x_labels=False)
    line_chart.title = "收盘价折线图"
    line_chart.x_labels = data["dates"]
    # X轴每隔20天显示一次
    N = 20
    line_chart.x_labels_major = data["dates"][::N]
    line_chart.add("收盘价", data["closes"])
    line_chart.render_to_file('收盘价折线图.svg')
json_file_path = "btc/btc_close_2017.json"
draw(read_json_data_from_file(json_file_path))