diff --git a/xautodl/log_utils/logger.py b/xautodl/log_utils/logger.py
index 3da517d..71f3866 100644
--- a/xautodl/log_utils/logger.py
+++ b/xautodl/log_utils/logger.py
@@ -156,7 +156,7 @@ class Logger(object):
         hist.max = float(np.max(values))
         hist.num = int(np.prod(values.shape))
         hist.sum = float(np.sum(values))
-        hist.sum_squares = float(np.sum(values ** 2))
+        hist.sum_squares = float(np.sum(values**2))
 
         # Drop the start of the first bin
         bin_edges = bin_edges[1:]
diff --git a/xautodl/procedures/optimizers.py b/xautodl/procedures/optimizers.py
index 3dd1f00..813ba8d 100644
--- a/xautodl/procedures/optimizers.py
+++ b/xautodl/procedures/optimizers.py
@@ -155,7 +155,7 @@ class ExponentialLR(_LRScheduler):
             if self.current_epoch >= self.warmup_epochs:
                 last_epoch = self.current_epoch - self.warmup_epochs
                 assert last_epoch >= 0, "invalid last_epoch : {:}".format(last_epoch)
-                lr = base_lr * (self.gamma ** last_epoch)
+                lr = base_lr * (self.gamma**last_epoch)
             else:
                 lr = (
                     self.current_epoch / self.warmup_epochs
diff --git a/xautodl/xmisc/scheduler_utils.py b/xautodl/xmisc/scheduler_utils.py
index df0ffdf..773fca8 100644
--- a/xautodl/xmisc/scheduler_utils.py
+++ b/xautodl/xmisc/scheduler_utils.py
@@ -122,7 +122,7 @@ class ExponentialParamScheduler(ParamScheduler):
         self._decay = decay
 
     def __call__(self, where: float) -> float:
-        return self._start_value * (self._decay ** where)
+        return self._start_value * (self._decay**where)
 
 
 class LinearParamScheduler(ParamScheduler):