Finishing the Airfoil Plotter

import requests
import matplotlib.pyplot as plt
def plot_airfoil(x_coordinates: list, y_coordinates: list, plot_title: str) -> None:
    """
    Plot the airfoil coordinates given the list of coordinates
    :param x_coordinates: list of airfoil's x coordinates
    :param y_coordinates: list of airfoil's y coordinates
    :param plot_title: str to title as the plot's title
    :return: None
    """
    plt.plot(x_coordinates, y_coordinates, 'k-')
    plt.title('{} airfoil'.format(plot_title))
    plt.style.use('default')
    plt.xlim(-0.50, 1.25)
    plt.ylim(-1, 1)
    #plt.show()
    plt.savefig("output/chap4_6.png")
def get_airfoil_coords(airfoil: str) -> tuple:
    """
    Get airfoil coords from UIUC website
    https://m-selig.ae.illinois.edu/ads/coord/__.dat
    :param airfoil: str of airfoil types
    :return: tuple of ([x coords], [y coords], plot_title)
    """
    url = 'https://m-selig.ae.illinois.edu/ads/coord/{}.dat'.format(
                                                   airfoil.lower())
    response_text = requests.get(url).text
    
    all_text = response_text.split('\n')
    x_coordinates, y_coordinates = [], []
    plot_title = ''
    for index, line in enumerate(all_text):
        if index == 0:
            plot_title = line.strip()
        else:
            try:
                line = line.strip()
                x, y = line.split(' ' * line.count(' ')) # line changed
                x = float(x.strip())
                y = float(y.strip())
                if x <= 1.0 and y <= 1.0:                # line changed
                    x_coordinates.append(x)
                    y_coordinates.append(y)
            except ValueError:
                continue
                
        return x_coordinates, y_coordinates, plot_title
air_foil = 'not_an_airfoil_name'
x_values, y_values, title = get_airfoil_coords(air_foil)
plot_airfoil(x_values, y_values, title)