Add live_info_terminal, closes #436 (#441)

* Add live_info_terminal, closes #436

* Add time

* rename var

* Add doc-string

adaptive/runner.py

@@ -776,6 +776,55 @@ def live_info(self, *, update_interval: float = 0.1) -> None:
         """
         return live_info(self, update_interval=update_interval)
 
+    def live_info_terminal(
+        self, *, update_interval: float = 0.5, overwrite_previous: bool = True
+    ) -> asyncio.Task:
+        """
+        Display live information about the runner in the terminal.
+
+        This function provides a live update of the runner's status in the terminal.
+        The update can either overwrite the previous status or be printed on a new line.
+
+        Parameters
+        ----------
+        update_interval : float, optional
+            The time interval (in seconds) at which the runner's status is updated in the terminal.
+            Default is 0.5 seconds.
+        overwrite_previous : bool, optional
+            If True, each update will overwrite the previous status in the terminal.
+            If False, each update will be printed on a new line.
+            Default is True.
+
+        Returns
+        -------
+        asyncio.Task
+            The asynchronous task responsible for updating the runner's status in the terminal.
+
+        Examples
+        --------
+        >>> runner = AsyncRunner(...)
+        >>> runner.live_info_terminal(update_interval=1.0, overwrite_previous=False)
+
+        Notes
+        -----
+        This function uses ANSI escape sequences to control the terminal's cursor position.
+        It might not work as expected on all terminal emulators.
+        """
+
+        async def _update(runner: AsyncRunner) -> None:
+            try:
+                while not runner.task.done():
+                    if overwrite_previous:
+                        # Clear the terminal
+                        print("\033[H\033[J", end="")
+                    print(_info_text(runner, separator="\t"))
+                    await asyncio.sleep(update_interval)
+
+            except asyncio.CancelledError:
+                print("Live info display cancelled.")
+
+        return self.ioloop.create_task(_update(self))
+
     async def _run(self) -> None:
         first_completed = asyncio.FIRST_COMPLETED
 
@@ -855,6 +904,43 @@ async def _saver():
         return self.saving_task
 
 
+def _info_text(runner, separator: str = "\n"):
+    status = runner.status()
+
+    color_map = {
+        "cancelled": "\033[33m",  # Yellow
+        "failed": "\033[31m",  # Red
+        "running": "\033[34m",  # Blue
+        "finished": "\033[32m",  # Green
+    }
+
+    overhead = runner.overhead()
+    if overhead < 50:
+        overhead_color = "\033[32m"  # Green
+    else:
+        overhead_color = "\033[31m"  # Red
+
+    info = [
+        ("time", str(datetime.now())),
+        ("status", f"{color_map[status]}{status}\033[0m"),
+        ("elapsed time", str(timedelta(seconds=runner.elapsed_time()))),
+        ("overhead", f"{overhead_color}{overhead:.2f}%\033[0m"),
+    ]
+
+    with suppress(Exception):
+        info.append(("# of points", runner.learner.npoints))
+
+    with suppress(Exception):
+        info.append(("# of samples", runner.learner.nsamples))
+
+    with suppress(Exception):
+        info.append(("latest loss", f'{runner.learner._cache["loss"]:.3f}'))
+
+    width = 30
+    formatted_info = [f"{k}: {v}".ljust(width) for i, (k, v) in enumerate(info)]
+    return separator.join(formatted_info)
+
+
 # Default runner
 Runner = AsyncRunner