Merge branch 'master' of https://github.com/talkpython/python-for-dotnet-developers-course

Author: mikeckennedy

apps/net/Ch5_nuget/Program.cs

@@ -34,7 +34,7 @@ public static void GetTitleRange()
             Console.ForegroundColor = ConsoleColor.White;
         }
 
-        public  static string GetEpisodeHtml(int episodeNumber, string url = null)
+        public static string GetEpisodeHtml(int episodeNumber, string url = null)
         {
             if (string.IsNullOrEmpty(url))
             {

apps/net/Ch9_Async/Program.cs

@@ -13,7 +13,7 @@ class MainClass
         public static void Main()
         {
             Console.ForegroundColor = ConsoleColor.White;
-            Console.WriteLine("Concurrent Web Scraper.");
+            Console.WriteLine("C# Concurrent Web Scraper.");
             var sw = Stopwatch.StartNew();
 
             GetTitleRange().Wait();

apps/py/.idea/dictionaries/screencaster.xml

@@ -1,3 +1,9 @@
+import os
+import sys
+
+folder = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
+sys.path.insert(0, folder)
+
 import flask
 from guitary.services import catalog_service
 

apps/py/ch07_web/guitary/app.py

@@ -0,0 +1,2 @@
+from guitary.app import app
+

apps/py/ch07_web/wsgi.py

@@ -24,13 +24,18 @@ def guitars(style: str = None):
     return flask.render_template('guitars.html', guitars=guitar_list)
 
 
-def main():
+def configure():
     session_factory.global_init('guitary.sqlite')
     session_factory.create_tables()
     data_loader.load_guitars_if_empty()
 
+
+def main():
+    configure()
     app.run(debug=True)
 
 
 if __name__ == '__main__':
     main()
+else:
+    configure()

apps/py/ch08_db/guitary/app.py

@@ -1,24 +1,34 @@
 from colorama import Fore
 import httpx
 import bs4
+import datetime
+from unsync import unsync
 
 
 def main():
-    print("Using Python packages")
+    print("Python async web scraper")
 
-    get_titles()
+    t0 = datetime.datetime.now()
+    get_titles().result()
+    dt = datetime.datetime.now() - t0
+    print(f"Finished in {dt.total_seconds():,.2f} seconds.")
 
 
-def get_html(n: int) -> str:
+@unsync
+async def get_html(n: int) -> str:
     print(Fore.YELLOW + f"Getting HTML for episode {n}...", flush=True)
     url = f'https://talkpython.fm/{n}'
 
-    resp = httpx.get(url)
-    resp.raise_for_status()
+    # The "async with" syntax ensures that all active connections are closed on exit.
+    async with httpx.AsyncClient() as client:
+        resp = await client.get(url)
+        resp.raise_for_status()
 
     return resp.text
 
 
+# @unsync                # <-- will run get_title_from_html() on a background thread.
+# @unsync(cpu_bound=True)  # <-- will run get_title_from_html() on a subprocess.
 def get_title_from_html(n: int, html: str) -> str:
     print(Fore.CYAN + f"Getting TITLE for episode {n}...", flush=True)
 
@@ -30,10 +40,24 @@ def get_title_from_html(n: int, html: str) -> str:
     return header.text.strip()
 
 
-def get_titles():
-    for n in range(220, 230):
-        html = get_html(n)
-        title = get_title_from_html(n, html)
+# async def get_titles():
+#     for n in range(220, 231):
+#         html = await get_html(n)
+#         title = get_title_from_html(n, html)
+#         print(Fore.GREEN + title)
+
+@unsync
+async def get_titles():
+    tasks = []
+    for n in range(220, 231):
+        task = get_html(n)
+        episode = n
+
+        tasks.append((episode, task))
+
+    for episode, task in tasks:
+        html = await task
+        title = get_title_from_html(episode, html)
         print(Fore.GREEN + title)
 
 

apps/py/ch10_async/ascrape.py

@@ -0,0 +1,46 @@
+from matplotlib import pyplot as plt
+from mpl_toolkits.mplot3d import Axes3D
+import numpy as np
+from scipy import integrate
+
+def solve_lorenz(sigma=10.0, beta=8./3, rho=28.0):
+    """Plot a solution to the Lorenz differential equations."""
+
+    max_time = 4.0
+    N = 30
+
+    fig = plt.figure()
+    ax = fig.add_axes([0, 0, 1, 1], projection='3d')
+    ax.axis('off')
+
+    # prepare the axes limits
+    ax.set_xlim((-25, 25))
+    ax.set_ylim((-35, 35))
+    ax.set_zlim((5, 55))
+    
+    def lorenz_deriv(x_y_z, t0, sigma=sigma, beta=beta, rho=rho):
+        """Compute the time-derivative of a Lorenz system."""
+        x, y, z = x_y_z
+        return [sigma * (y - x), x * (rho - z) - y, x * y - beta * z]
+
+    # Choose random starting points, uniformly distributed from -15 to 15
+    np.random.seed(1)
+    x0 = -15 + 30 * np.random.random((N, 3))
+
+    # Solve for the trajectories
+    t = np.linspace(0, max_time, int(250*max_time))
+    x_t = np.asarray([integrate.odeint(lorenz_deriv, x0i, t)
+                      for x0i in x0])
+    
+    # choose a different color for each trajectory
+    colors = plt.cm.viridis(np.linspace(0, 1, N))
+
+    for i in range(N):
+        x, y, z = x_t[i,:,:].T
+        lines = ax.plot(x, y, z, '-', c=colors[i])
+        plt.setp(lines, linewidth=2)
+    angle = 104
+    ax.view_init(30, angle)
+    plt.show()
+
+    return t, x_t