code: def get_number_of_particles():
      
      with open('dynac.short') as f:
          data_str = ''.join(line for line in f.readlines())
          num_of_parts = int(data_str.split('Simulation with')[1].strip().split()[0])
      return num_of_parts
docs: Queries the ``dynac.short`` file for the number of particles used in the
      simulation.