QuickDraw中的python3递归动画

Question

我有一个文本文件，里面有行星和它们对应的卫星/卫星，以及它们的轨道半径和周期，我想用它在quickdraw中创建一个类似于下面的动画：

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文本文件如下：

RootObject: Sun

Object: Sun
Satellites: Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune,Ceres,Pluto,Haumea,Makemake,Eris
Radius: 20890260
Orbital Radius: 0

Object: Miranda
Orbital Radius: 5822550
Radius: 23500
Period: 1.413

Object: Ariel
Orbital Radius: 8595000
Radius: 60000
Period: 2.520379

Object: Umbriel
Orbital Radius: 11983500
Radius: 60000
Period: 4.144177

Object: Titania
Orbital Radius: 19575000
Radius: 75000
Period: 8.7058

Object: Oberon
Orbital Radius: 26235000
Radius: 75000
Period: 13.463

Object: Uranus
Orbital Radius: 453572956
Radius: 2555900
Period: 30799
Satellites: Puck,Miranda,Ariel,Umbriel,Titania,Oberon

Object: Neptune
Orbital Radius: 550000000
Radius: 2476400
Period: 60190
Satellites: Triton

Object: Triton
Orbital Radius: 40000000
Radius: 135300
Period: -5.8

Object: Mercury
Orbital Radius: 38001200
Period: 87.9691
Radius: 243900.7

Object: Venus
Orbital Radius: 57477000
Period: 224.698
Radius: 605100.8

Object: Earth
Orbital Radius: 77098290
Period: 365.256363004
Radius: 637100.0
Satellites: Moon

Object: Moon
Orbital Radius: 18128500
Radius: 173700.10
Period: 27.321582

Object: Mars
Orbital Radius: 106669000
Period: 686.971
Radius: 339600.2
Satellites: Phobos,Deimos

Object: Phobos
Orbital Radius: 3623500.6
Radius: 200000
Period: 0.31891023

Object: Deimos
Orbital Radius: 8346000
Period: 1.26244
Radius: 200000.2

Object: Jupiter
Orbital Radius: 210573600
Period: 4332.59
Radius: 7149200
Satellites: Io,Europa,Ganymede,Callisto

Object: Ceres
Orbital Radius: 130995855
Period: 1679.67
Radius: 48700

Object: Io
Orbital Radius: 22000000
Period: 1.7691377186
Radius: 182100.3

Object: Europa
Orbital Radius: 36486200
Period: 3.551181
Radius: 156000.8

Object: Ganymede
Orbital Radius: 47160000
Period: 7.15455296
Radius: 263400

Object: Callisto
Orbital Radius: 69700000
Period: 16.6890184
Radius: 241000

Object: Saturn
Orbital Radius: 353572956
Period: 10759.22
Radius: 6026800
Satellites: Mimas,Enceladus,Tethys,Dione,Rhea,Titan,Iapetus

Object: Mimas
Orbital Radius: 8433396
Radius: 20600
Period: 0.9

Object: Enceladus
Orbital Radius: 10706000
Radius: 25000
Period: 1.4

Object: Tethys
Orbital Radius: 13706000
Radius: 50000
Period: 1.9

Object: Dione
Orbital Radius: 17106000
Radius: 56000
Period: 2.7

Object: Rhea
Orbital Radius: 24000000
Radius: 75000
Period: 4.5

Object: Titan
Orbital Radius: 50706000
Radius: 257600
Period: 15.945

Object: Iapetus
Radius: 75000
Orbital Radius: 72285891
Period: 79

我已经将我的原始代码(长得离谱)改成了这个更短的代码：(归功于sudo_O所有出色的help)

file = open("data1.txt","r")

def data(file):
    d = {}
    for line in file:
        if line.strip() != '':
            key,value = line.split(":")
            if key == 'RootObject':
                continue
            if key == 'Object':                
                obj = value.strip()
                d[obj]={}
            else:
                d[obj][key] = value.strip()
    return d

planets = data(file)

print(planets)

我最大的问题是，我不知道如何编写代码从文件中导入数据，并通过recursion使用它来创建类似于所示动画的动画。我一直被告知，解决方案非常简单，代码实际上令人惊讶地短，但我不知道如何做到这一点，这实际上非常令人沮丧。

这是我的一个圆的代码，但它似乎太复杂了……

import math

print("circle",400,300,50)

print("flush false")

centreX=400
centreY=300
radius=100
angle=math.pi/2

while True:
    print("color 0 0 0")
    print("clear")
    print("color 255 0 255")
    print("circle",centreX,centreY,radius)
    childX=math.sin(angle)*radius*1.5+centreX
    childY=math.cos(angle)*radius*1.5+centreY
    print("circle",childX,childY,radius/2)
    print("refresh")
    angle+=0.01

scale的代码：

scale=250/max([dict[planets]["Orbital Radius"] for x in dict if "Orbital Radius" in dict[planets]])

环绕行星运行的代码：

print("flush false")
scale=250/max([dict[planets]["Orbital Radius"] for x in dict if "Orbital Radius" in dict[planets]])
t=0
x=400
y=300
while True:
    print("refresh")
    print("colour 0 0 0")
    print("clear")
    print("colour 255 255 255")
    print("fillcircle",x,y,dict['Sun']['Radius']*scale)
    print("text ", "\"Sun\"",x+dict['Sun']['Radius']*scale,y)
    r_earth=dict['Earth']['Orbital Radius']*scale;
    print("circle",x,y,r_earth)
    r_X=x+math.sin(t*2*math.pi/dict['Earth']['Period'])*r_earth
    r_Y=y+math.cos(t*2*math.pi/dict['Earth']['Period'])*r_earth
    print("fillcircle",r_X,r_Y,dict['Earth']['Radius']*scale)
    print("text ", "\"Earth\"",r_X+dict['Earth']['Radius']*scale,r_Y)
    t+=0.02

然而，这段代码不能很好地工作，作为一个初学者，我已经达到了这个问题的极限……

最后的努力!！这能行得通吗？

print("flush false")
scale = 250/max([dict[planets]["Orbital Radius"] for x in dict if "Orbital Radius" in dict[planets]])
t = 0
x = 400
y = 300
print("fillcircle",400,300,dict['Sun']['Radius']*scale)
print("text ", "\"Sun\"",x+dict['Sun']['Radius']*scale,y)


while True:
    r_new = dict['Object']['Orbital Radius']*scale
    print("circle",x,y,r_new)
    r_X = x + math.sin(t*2*math.pi/dict['Object']['Period'])*r_new
    r_Y = y + math.cos(t*2*math.pi/dict['Object']['Period'])*r_new
    print("fillcircle",r_X,r_Y,dict['Object']['Radius']*scale)
    print("text ",Object,r_X+dict['Object']['Radius']*scale,r_Y)
    t += 0.02
    if planets['Object']['Satellites'] = 0
        return
    else:
        r_sat = dict['Object']['Satellites']['Orbital Radius']*scale
        print("circle",x,y,r_sat)
        r_satX = x + math.sin(t*2*math.pi/dict['Object']['Satellites']['Period'])*r_sat
        r_satY = y + math.cos(t*2*math.pi/dict['Object']['Satellites']['Period'])*r_sat
        print("fillcircle",r_satX,r_satY,dict['Object']['Satellites']['Radius']*scale)
        print("text ",['Object']['Satellites'],r_satX+dict['Object']['Satellites']['Radius']*scale,r_satY)
        t += 0.02

Answer 1

First problem递归-递归函数是调用自己的函数！这方面的一个简单示例是倒计时函数，例如：

def countdown(n):
    # counting down the recursive way! 
    if n > 0:
        print n
        countdown(n-1)
    else:
        return

调用countdown(10)将打印10, 9, 8,.., 2, 1。

您可以看到，countdown被传递了一个数字n，它所做的就是打印这个数字，然后调用它自己，但这次传递的是n-1。只有在传递了n=0之后，它才不再需要做任何事情，所以每次递归调用都会被返回。对于您的字典情况(为避免混淆，我们称其为字典库)，recursive打印方法为：

第一个dictionary.

• Recursively调用本身，将整个库传递给打印routine.

• Print，然后传递减去第一个字典的库。当库没有更多的词典可打印时，

• 返回。

如下所示：

def recursive_print(dic):

    if len(dic) > 0:                  # If dictionaries in library > 0 
        print dic.keys()[0]           # Print the key i.e Earth
        print dic[dic.keys()[0]]      # Print the dictionary value for i.e Earth
        dic.popitem()                 # Remove the Earth dictionary from library
        recursive_print(dic)          # Recursive call 
    else:
        return                        # Printed all, return up the stack.


planets = data(file)
recursive_print(planets)

下一步不是打印当前格式的字典，而是进行一些计算/转换，这样输出就是有效的quickdraw输入，就像使用quickdraw打印圆形的代码一样。

您将需要担心比例，以确保所有对象适合绘图表面找到具有最大Orbital Radius的天体，并使用它来计算比例。

使用类似于您的代码的列表理解，我们可以找到最大值：

max([planet[key]['Orbital Radius'] for key in planet])

>>> 8595000

scale = gridsize/max([planet[key]['Orbital Radius'] for key in planet])