Python3 recursive animation in quickdraw

Question

I have a text file with planets and their respective moons / satellites along with their orbital radius and period, and I would like to use it to create quickdraw animations similar to the one below:

The text file is as follows:

 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 

I changed my source code (which was ridiculously longer) to this shorter one: (credit for sudo_O for all its amazing 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) 

My biggest problem is that I don’t know how to write code that imports data from a file and uses it through recursion to create an animation similar to the one shown. They constantly tell me that the solution is quite simple, and the code is actually surprisingly short, but I have no idea how to do this, and it is really very unpleasant.

Here is my code for a circle revolving around a circle, but it seems too complicated ...

 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 

scaling code:

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

Code for orbiting planets:

 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 

this code does not work very well, but as a beginner, I am within my limits for this problem ...

last ditch effort !! could this work?

 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

The first recursion of the problem - the recursive function - is the one that calls itself! A simple example of this is a countdown function such as:

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

A call to countdown(10) will print 10, 9, 8,.., 2, 1 .

You can see that countdown is passed the number n , and all it does is print this number and then call it itself, but pass n-1 this time. Only once is n=0 passed, it has nothing to do so that every recursive call returns. For a dictionary of dictionaries (let's call it a library of dictionaries to avoid confusion). recursive printing approach:

• Transfer the entire library to the printing procedure. A.
• Print the first dictionary.
• Call yourself recursively and pass the library minus the first dictionary.
• Refund if there are no more print dictionaries in the library. A.

Something like that:

 def recursive_print(dic): if len(dic) > 0: # If dictionaries in library > 0 print dic.keys()[0] # Print the key ie Earth print dic[dic.keys()[0]] # Print the dictionary value for ie 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) 

The next step is, instead of printing the dictionaries in the current format, you would do some calculations / conversions so that the output is a valid quickdraw , like the code you already used to print circles using quickdraw .

You will need to worry about the scale so that all objects located on the drawing surface find the celestial body with the largest Orbital Radius and use it to calculate the scale.

Using a list comprehension similar to your code, we can find the highest value:

 max([planet[key]['Orbital Radius'] for key in planet]) >>> 8595000 scale = gridsize/max([planet[key]['Orbital Radius'] for key in planet])