Python 乌龟图答案

【问题标题】：Python turtle graphPython 乌龟图
【发布时间】：2014-12-02 21:55:35
【问题描述】：

谁能帮我清理我的图表。当我绘制 y 轴时，我希望整数四舍五入到最接近的百分之一。此外，在每个条下我需要标记“a”-“z”：总共 26 个条：

def letterFreqPlot(freqList):    
    border = 5
    t = turtle.Turtle()
    t.pensize(3)
    screen = t.getscreen()
    maxheight = max(freqList)
    numbers = len(freqList)
    screen.setworldcoordinates(0-border,-.05,numbers+1,maxheight+.1)
    t.goto(0,0)
    t.hideturtle()
    t.speed(0)
    t.lt(90)
    t.fd(maxheight)
    t.fd(-maxheight)
    t.right(90)
    for item in freqList:
        t.fillcolor("blue")
        t.begin_fill()
        for dist in [1, item, 1, item]:           
            t.fd(dist)
            t.lt(90)
        t.fd(1)
        t.end_fill()
    t.goto(0,0)
    t.lt(90)
    for i in freqList:
        t.fd(i)
        t.lt(90)
        t.fd(3)
        t.write(float(i))
        t.fd(-3)
        t.rt(90)
        t.fd(-i)
    print('Click to exit')
    screen.exitonclick()
freqList = letterFreq(words)
letterFreqPlot(freqList)

频率列表：

[0.09090909090909091, 0.0, 0.0, 0.09090909090909091, 0.18181818181818182, 0.0, 0.0, 0.0, 0.045454545454545456, 0.0, 0.0, 0.0, 0.0, 0.045454545454545456, 0.045454545454545456, 0.045454545454545456, 0.045454545454545456, 0.18181818181818182, 0.045454545454545456, 0.09090909090909091, 0.045454545454545456, 0.0, 0.045454545454545456, 0.0, 0.0, 0.0]

【问题讨论】：

将整数四舍五入到最接近的百分之一尚不清楚。你是说花车吗？
我认为您的频率列表应该是原始计数。如果将 0.045 舍入为 0.04 或 0.05，则将不再是 0.09 的一半，就像现在一样。如果在阅读文档后需要turtle.write方法的帮助，请查看编写文本的turtledemo示例，例如时钟演示中的tick()函数。

标签： python python-3.x turtle-graphics

【解决方案1】：

以下是我尝试将您想要的功能添加到图表以及稍微优化绘图代码并添加功能：

from turtle import Turtle, Screen

BORDER = 5
FONT = ("Arial", 12, "normal")
FLOAT_FORMAT = "0.2f"
PENSIZE = 3

def letterFrequency(string):
    counter = dict()

    length = ord('z') - ord('a') + 1

    for ordinal in range(length):
        counter[chr(ordinal + ord('a'))] = 0

    count = 0

    for character in string:
        if character.isalpha():
            counter[character] += 1
            count += 1

    return [counter[key] / count for key in sorted(counter)]


def letterFreqPlot(turtle, canvas, string):

    turtle.pensize(PENSIZE)

    frequencyList = letterFrequency(string)

    maxheight = max(frequencyList)
    numbers = len(frequencyList)

    canvas.setworldcoordinates(-BORDER, -.05, numbers + 1, maxheight + 0.1)

    turtle.hideturtle()

    for frequency in sorted(set(frequencyList)):
        turtle.penup()
        turtle.home()
        turtle.lt(90)
        turtle.pendown()
        turtle.forward(frequency)
        turtle.left(90)
        turtle.forward(3)
        turtle.write(format(frequency, FLOAT_FORMAT), font=FONT)

    turtle.penup()
    turtle.home()
    turtle.sety(-0.0125)

    for i, frequency in enumerate(frequencyList):
        turtle.forward(0.5)
        turtle.write(chr(ord('a') + i), font=FONT)
        turtle.forward(0.5)

    turtle.home()
    turtle.goto(len(frequencyList) / 2, -0.025)
    turtle.write(string, align="center", font=FONT)

    turtle.home()
    turtle.fillcolor("blue")
    turtle.pendown()

    for frequency in frequencyList:
        if frequency > 0.0:
            turtle.begin_fill()
            for distance in [1, frequency] * 2:
                turtle.forward(distance)
                turtle.left(90)
            turtle.end_fill()
        turtle.forward(1)


yertle = Turtle()
yertle.speed("fastest")

screen = Screen()

letterFreqPlot(yertle, screen, "an opportunity to teach is an opportunity to learn")

screen.exitonclick()

我没有让绘图代码回溯那么多，而是使用turtle.home() 来重置起点和方向。为了好玩，我还添加了一个简单的 letterFrequency() 代码模拟。我收集了许多常量，但沿着这些思路还有更多工作要做。

顺便说一句，你是我见过的setworldcoordinates() 最好的例子之一。

【讨论】：