1 files changed, 65 insertions, 0 deletions
diff --git a/examples/progress-bar/a-lot-of-parallel-tasks.py b/examples/progress-bar/a-lot-of-parallel-tasks.py
new file mode 100755
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+++ b/examples/progress-bar/a-lot-of-parallel-tasks.py
@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+"""
+More complex demonstration of what's possible with the progress bar.
+"""
+import random
+import threading
+import time
+
+from prompt_toolkit import HTML
+from prompt_toolkit.shortcuts import ProgressBar
+
+
+def main():
+    with ProgressBar(
+        title=HTML("<b>Example of many parallel tasks.</b>"),
+        bottom_toolbar=HTML("<b>[Control-L]</b> clear  <b>[Control-C]</b> abort"),
+    ) as pb:
+
+        def run_task(label, total, sleep_time):
+            """Complete a normal run."""
+            for i in pb(range(total), label=label):
+                time.sleep(sleep_time)
+
+        def stop_task(label, total, sleep_time):
+            """Stop at some random index.
+
+            Breaking out of iteration at some stop index mimics how progress
+            bars behave in cases where errors are raised.
+            """
+            stop_i = random.randrange(total)
+            bar = pb(range(total), label=label)
+            for i in bar:
+                if stop_i == i:
+                    bar.label = f"{label} BREAK"
+                    break
+                time.sleep(sleep_time)
+
+        threads = []
+
+        for i in range(160):
+            label = "Task %i" % i
+            total = random.randrange(50, 200)
+            sleep_time = random.randrange(5, 20) / 100.0
+
+            threads.append(
+                threading.Thread(
+                    target=random.choice((run_task, stop_task)),
+                    args=(label, total, sleep_time),
+                )
+            )
+
+        for t in threads:
+            t.daemon = True
+            t.start()
+
+        # Wait for the threads to finish. We use a timeout for the join() call,
+        # because on Windows, join cannot be interrupted by Control-C or any other
+        # signal.
+        for t in threads:
+            while t.is_alive():
+                t.join(timeout=0.5)
+
+
+if __name__ == "__main__":
+    main()