pytec: plot.py: Add main function

pytec/plot.py

@@ -4,6 +4,8 @@ import matplotlib.animation as animation
 from threading import Thread, Lock
 from pytec.client import Client
 
+
+def main():
     TIME_WINDOW = 300.0
 
     tec = Client()
@@ -116,7 +118,7 @@ def animate(i):
             margin_y = 0.01 * (max_y - min_y)
             ax.set_ylim(min_y - margin_y, max_y + margin_y)
 
-    global legend
+        nonlocal legend
         legend.remove()
         legend = ax.legend()
 
@@ -126,3 +128,7 @@ ani = animation.FuncAnimation(
     plt.show()
     quit = True
     thread.join()
+
+
+if __name__ == "__main__":
+    main()