random_walk.py

from random import choice

class RandomWalk:
    """A class to generate random walks."""
 
    def __init__(self, num_points=5000):
        """Initialize attributes of a walk."""
        self.num_points = num_points
    
        # All walks start at (0, 0).
        self.x_values = [0]
        self.y_values = [0]
    
    def fill_walk(self):
        """Calculate all the points in the walk."""
    
        # Keep taking steps until the walk reaches the desired length.
        while len(self.x_values) < self.num_points:
        
            # Decide which direction to go and how far
            # to go in that direction.
            x_step = self._get_step()
            y_step = self._get_step()
        
            # Reject moves that go nowhere.
            if x_step == 0 and y_step == 0:
                continue
        
            # Calculate the new position.
            x = self.x_values[-1] + x_step
            y = self.y_values[-1] + y_step
        
            self.x_values.append(x)
            self.y_values.append(y)

    def _get_step(self):
        """Calculate the direction and distance of a step"""
        direction = choice([1, -1])
        distance = choice(range(0, 5))
        return direction * distance