old_contents: from argparse import ArgumentParser
  from matplotlib import pyplot as plt
  from boids import Flock
  from matplotlib import animation
  import yaml
  import os
  import numpy as np
  
  def process():
  	parser = ArgumentParser(description = "Boids")
      
  	parser.add_argument('--config', dest = 'file')
  	
  	if len(sys.argv) == 1:
  		parser.print_help()
  		sys.exit(1)
  
  	arguments= parser.parse_args()
      
  	print(arguments.file)
  
  	boids=Flock('config.yaml')
  
  	figure=plt.figure()
  	axes=plt.axes(xlim=(-500,1500), ylim=(-500,1500))
  	handle = lambda frame: animate(boids, scatter) 
  	scatter=axes.scatter(boids.positions[0,:],boids.positions[1,:])
  
  	anim = animation.FuncAnimation(figure, handle,
                                 frames=50, interval=50)
  
  	plt.show()
     
  def animate(boids, scatter):
   
     boids.update_boids()
     scatter.set_offsets(zip(boids.positions[0,:],boids.positions[1,:]))
  
  
  if __name__ == "__main__":
      process()    
  
new_contents: from argparse import ArgumentParser
  from matplotlib import pyplot as plt
  from boids import Flock
  from matplotlib import animation
  import yaml
  import os
  import numpy as np
  import sys
  
  def process():
  	parser = ArgumentParser(description = "Boids")
      
  	parser.add_argument('--config', dest = 'file')
  	
  	if len(sys.argv) == 1:
  		parser.print_help()
  		sys.exit(1)
  
  	arguments= parser.parse_args()
      
  	print(arguments.file)
  
  	boids=Flock('config.yaml')
  
  	figure=plt.figure()
  	axes=plt.axes(xlim=(-500,1500), ylim=(-500,1500))
  	handle = lambda frame: animate(boids, scatter) 
  	scatter=axes.scatter(boids.positions[0,:],boids.positions[1,:])
  
  	anim = animation.FuncAnimation(figure, handle,
                                 frames=50, interval=50)
  
  	plt.show()
     
  def animate(boids, scatter):
   
     boids.update_boids()
     scatter.set_offsets(zip(boids.positions[0,:],boids.positions[1,:]))
  
  
  if __name__ == "__main__":
      process()    
  
subject: Update command.py to print help message