humanize time delta into a proper format rather than 48964518 sec. (#658)

* humanize time delta into a proper format rather than 48964518 sec.

* remove 3rd party dependency

* handle non-integer cases

* add documentation

* proper named function

* use datetime.timedelta

tensorpack/callbacks/group.py

@@ -10,6 +10,7 @@ import traceback
 from .base import Callback
 from .hooks import CallbackToHook
 from ..utils import logger
+from ..utils.utils import humanize_time_delta
 
 __all__ = ['Callbacks']
 
@@ -30,13 +31,14 @@ class CallbackTimeLogger(object):
         self.add(name, time.time() - s)
 
     def log(self):
+
         """ log the time of some heavy callbacks """
         if self.tot < 3:
             return
         msgs = []
         for name, t in self.times:
             if t / self.tot > 0.3 and t > 1:
-                msgs.append("{}: {:.3f}sec".format(name, t))
+                msgs.append(name + ": " + humanize_time_delta(t))
         logger.info(
             "Callbacks took {:.3f} sec in total. {}".format(
                 self.tot, '; '.join(msgs)))

tensorpack/train/base.py

@@ -11,6 +11,7 @@ import six
 from ..callbacks import (
     Callback, Callbacks, Monitors, TrainingMonitor)
 from ..utils import logger
+from ..utils.utils import humanize_time_delta
 from ..utils.argtools import call_only_once
 from ..tfutils import get_global_step_value
 from ..tfutils.tower import TowerFuncWrapper
@@ -253,8 +254,8 @@ class Trainer(object):
                         self.run_step()  # implemented by subclass
                         self._callbacks.trigger_step()
                     self._callbacks.after_epoch()
-                    logger.info("Epoch {} (global_step {}) finished, time:{:.2f} sec.".format(
-                        self.loop.epoch_num, self.loop.global_step, time.time() - start_time))
+                    logger.info("Epoch {} (global_step {}) finished, time:{}.".format(
+                        self.loop.epoch_num, self.loop.global_step, humanize_time_delta(time.time() - start_time)))
 
                     # trigger epoch outside the timing region.
                     self._callbacks.trigger_epoch()

tensorpack/utils/utils.py

@@ -6,7 +6,7 @@ import os
 import sys
 from contextlib import contextmanager
 import inspect
-from datetime import datetime
+from datetime import datetime, timedelta
 from tqdm import tqdm
 import numpy as np
 
@@ -16,9 +16,54 @@ __all__ = ['change_env',
            'fix_rng_seed',
            'get_tqdm',
            'execute_only_once',
+           'humanize_time_delta'
            ]
 
 
+def humanize_time_delta(sec):
+    """Humanize timedelta given in seconds
+
+    Args:
+        sec (float): time difference in seconds.
+
+    Examples:
+
+        Several time differences as a human readable string
+
+    .. code-block:: python
+
+        print humanize_seconds(1)                                   # 1 second
+        print humanize_seconds(60 + 1)                              # 1 minute 1 second
+        print humanize_seconds(87.6)                                # 1 minute 27 seconds
+        print humanize_seconds(0.01)                                # 0.01 seconds
+        print humanize_seconds(60 * 60 + 1)                         # 1 hour 0 minutes 1 second
+        print humanize_seconds(60 * 60 * 24 + 1)                    # 1 day 0 hours 0 minutes 1 second
+        print humanize_seconds(60 * 60 * 24 + 60 * 2 + 60*60*9+ 3)  # 1 day 9 hours 2 minutes 3 seconds
+
+    Returns:
+        time difference as a readable string
+    """
+    time = datetime(2000, 1, 1) + timedelta(seconds=int(sec))
+    units = ['day', 'hour', 'minute', 'second']
+    vals = [time.day - 1, time.hour, time.minute, time.second]
+    if sec < 60:
+        vals[-1] = sec
+
+    def _format(v, u):
+        return "{} {}{}".format(v, u, "s" if v > 1 else "")
+
+    required = False
+    ans = []
+    for v, u in zip(vals, units):
+        if not required:
+            if v > 0:
+                required = True
+                ans.append(_format(v, u))
+        else:
+            ans.append(_format(v, u))
+    return " ".join(ans)
+
+
 @contextmanager
 def change_env(name, val):
     """