keras: fix resume from `initial_epoch`

- set initial epochs
- update tests

tests/tests_keras.py

@@ -38,9 +38,7 @@ def test_keras(capsys):
                 desc="training",
                 data_size=len(x),
                 batch_size=batch_size,
-                verbose=0,
-            )],
-    )
+                verbose=0)])
     _, res = capsys.readouterr()
     assert "training: " in res
     assert "{epochs}/{epochs}".format(epochs=epochs) in res
@@ -59,9 +57,7 @@ def test_keras(capsys):
                 desc="training",
                 data_size=len(x),
                 batch_size=batch_size,
-                verbose=2,
-            )],
-    )
+                verbose=2)])
     _, res = capsys.readouterr()
     assert "training: " in res
     assert "{epochs}/{epochs}".format(epochs=epochs) in res
@@ -74,8 +70,7 @@ def test_keras(capsys):
         epochs=epochs,
         batch_size=batch_size,
         verbose=False,
-        callbacks=[TqdmCallback(desc="training", verbose=2)],
-    )
+        callbacks=[TqdmCallback(desc="training", verbose=2)])
     _, res = capsys.readouterr()
     assert "training: " in res
     assert "{epochs}/{epochs}".format(epochs=epochs) in res
@@ -90,12 +85,9 @@ def test_keras(capsys):
         epochs=epochs,
         batch_size=batch_size,
         verbose=False,
-        callbacks=[TqdmCallback(
-            desc="training",
-            verbose=2
-        )],
-    )
+        callbacks=[TqdmCallback(desc="training", verbose=0,
+                                miniters=1, mininterval=0, maxinterval=0)])
     _, res = capsys.readouterr()
     assert "training: " in res
+    assert "{epochs}/{epochs}".format(epochs=initial_epoch - 1) not in res
     assert "{epochs}/{epochs}".format(epochs=epochs) in res
-    assert "{batches}/{batches}".format(batches=batches) in res

tqdm/keras.py

@@ -74,7 +74,8 @@ class TqdmCallback(keras.callbacks.Callback):
 
     def on_epoch_begin(self, epoch, *_, **__):
         if self.epoch_bar.n < epoch:
-            self.epoch_bar.update(epoch-self.epoch_bar.n)
+            ebar = self.epoch_bar
+            ebar.n = ebar.last_print_n = ebar.initial = epoch
         if self.verbose:
             params = self.params.get
             total = params('samples', params(