我们用Python来做一个天气时钟。也就是既能显示时间，也能显示未来12小时天气。我们的产品设计效果如下图：
一、时钟部分
这个天气时钟首先我们先做时钟部分。
时钟有时针、分针和秒针。这里用来绘制用到了Python Trutle库。以小时针为例。我们先
- 拿起画笔pen.penup()
- 笔移动到表盘中心点pen.goto(global_x_shift, global_y_shift)
- 带上笔的颜色, pen.color(hour_color)
- 设置笔的初始方向 pen.setheading(90)
- 设置笔的顺时针选择角度angle，对于时针来说就是angele=(hour /12)*360+(minute/60)*30
- 然后向右旋转角度pen.rt(angle)
- pen.pendown()放下笔开始绘画
- pen.fd(hour_hand) 向前绘制长度hour_hand。
| # draw a clock using the pen i created | |
| def draw_clock(hour, minute, second, pen): | |
| pen.hideturtle() | |
| # Draw the hour han | |
| # 有关Python Turtle常用的操作见http://www.cse.msu.edu/~ldillon/cse-ctl/Spring2015/Meeting07/turtleCheatSheet.pdf | |
| pen.penup() # 暂停绘画，和底下的pendown是一对 | |
| pen.goto(global_x_shift, global_y_shift) | |
| pen.color(hour_color) | |
| pen.pensize(6) # 小时针的宽度 | |
| pen.setheading(90) # 设置角度，0(east), 90(north), 180(west), 270(south) | |
| angle = (hour / 12) * 360 + (minute/60) * 30 # 根据当前时间,小时针应该便宜的角度 | |
| pen.rt(angle) # 向右/顺时针旋转角度，turtle.rt和turtle.right一样 | |
| pen.pendown() # 开始绘画，和上面的penup是一对 | |
| pen.fd(hour_hand) # 小时针的长度，向前绘制，turtle.fd同turtle.forward | |
| # Draw the minute hand | |
| pen.penup() | |
| pen.goto(global_x_shift, global_y_shift) | |
| pen.color(minute_color) | |
| pen.setheading(90) | |
| angle = (minute / 60.0) * 360 # optional + (s/60) * 6 | |
| pen.rt(angle) | |
| pen.pendown() | |
| pen.fd(minute_hand) | |
| # Draw the second hand | |
| pen.penup() | |
| pen.goto(global_x_shift, global_y_shift) | |
| pen.color(second_color) | |
| pen.setheading(90) | |
| angle = (second / 60) * 360 | |
| pen.rt(angle) | |
| pen.pendown() | |
| pen.fd(second_hand) |
二、未来12小时天气
获取未来12小时天气预报这个update_forecast函数，我们通过拉取openweathermap的接口，得到了温度，体感温度，风速和天气类型图标。
这些天气数值和图标准备好之后。会放在数组待用。
| def update_forecast(): | |
| global hour_cursor | |
| # weather ID breakdown https://openweathermap.org/weather-conditions | |
| # use https://ezgif.com/maker for gif conversion | |
| logging.debug("---- update_forecast() ----") | |
| hour_cursor = int(time.strftime("%I")) # %I表示12小时制 | |
| meridiem = time.strftime('%p') # %p表示上午AM或者下午PM | |
| logging.debug("hour_cursor: " + str(hour_cursor)) | |
| for num in range(12): | |
| # current hour | |
| logging.debug("current hour: " + str(hour_cursor) + " " + meridiem) | |
| # forecast hour | |
| logging.debug("forecast hour: " + str(int(hour_cursor)+num)) | |
| logging.debug("temperature: " + str(data["hourly"][num]["temp"])) | |
| logging.debug("feels like: " + str(data["hourly"][num]["feels_like"])) | |
| logging.debug("wind speed: " + str(data["hourly"][num]["wind_speed"])) | |
| logging.debug(data["hourly"][num]["weather"][0]["description"]) | |
| logging.debug("weather ID: " + str(data["hourly"][num]["weather"][0]["id"])) | |
| logging.debug("POP: " + str(data["hourly"][num]["pop"])) | |
| if 'rain' not in data["hourly"][num]: | |
| logging.debug("no rain data") | |
| else: | |
| logging.debug("rain: " + str(data["hourly"][num]["rain"])) | |
| temp_array[num] = data["hourly"][num]["temp"] # 温度 | |
| temp_feel_array[num] = data["hourly"][num]["feels_like"] # 体感温度 | |
| wind_array[num] = data["hourly"][num]["wind_speed"] # 风速 | |
| id_array[num] = data["hourly"][num]["weather"][0]["id"] # 天气icon id，见https://openweathermap.org/weather-conditions | |
| path_theme = os.path.join(path, theme) | |
| if 232 >= id_array[num] >= 200: | |
| idImage_array[num] = os.path.join(path_theme, "11d@2x.gif") | |
| elif 321 >= id_array[num] >= 300: | |
| idImage_array[num] = os.path.join(path_theme, "09d@2x.gif") | |
| elif 504 >= id_array[num] >= 500: | |
| idImage_array[num] = os.path.join(path_theme, "10d@2x.gif") | |
| elif id_array[num] == 511: | |
| idImage_array[num] = os.path.join(path_theme, "13d@2x.gif") | |
| elif 531 >= id_array[num] >= 520: | |
| idImage_array[num] = os.path.join(path_theme, "09d@2x.gif") | |
| elif 622 >= id_array[num] >= 600: | |
| idImage_array[num] = os.path.join(path_theme, "13d@2x.gif") | |
| elif 781 >= id_array[num] >= 701: | |
| idImage_array[num] = os.path.join(path_theme, "50d@2x.gif") | |
| elif id_array[num] == 800: | |
| idImage_array[num] = os.path.join(path_theme, "01d@2x.gif") | |
| elif id_array[num] == 801: | |
| idImage_array[num] = os.path.join(path_theme, "02d@2x.gif") | |
| elif id_array[num] == 802: | |
| idImage_array[num] = os.path.join(path_theme, "03d@2x.gif") | |
| elif id_array[num] == 803 or id_array[num] == 804: | |
| idImage_array[num] = os.path.join(path_theme, "04d@2x.gif") | |
| else: | |
| logging.error("Invalid weather ID") | |
| logging.debug(temp_array) | |
| logging.debug(id_array) | |
| logging.debug(idImage_array) | |
| for image in idImage_array: | |
| wn.addshape(image) # 画布上画上天气图标 | |
天气icon放置的位置就是原本时钟上的小时数位置。也就是x和y坐标通过公式计算：
| hour_x = [] | |
| hour_y = [] | |
| for i in range(60, -300, -30): | |
| i_r = math.radians(i) | |
| hour_x.append((math.cos(i_r)*radius)) | |
| hour_y.append((math.sin(i_r)*radius)) |
三、总结
完整的程序我放在了这里：weatherClock/weatherClock.py at master · lumanyu/weatherClock (github.com)
本程序通过小时和天气的创新融合，运用程序员的技能做了一个实用工具。