Tensorflow 2 /Google Colab / EfficientNet Training - AttributeError: 'Node' object has no attribute 'output_masks' - tensorflow

Question

I am trying to train EfficientNetB1 on Google Colab and constantly running into different issues with correct import statements from Keras or Tensorflow.Keras, currently this is how my imports look like
import tensorflow as tf
from tensorflow.keras import backend as K
from tensorflow.keras.preprocessing.image import ImageDataGenerator
from tensorflow.python.keras.layers.pooling import AveragePooling2D
from tensorflow.keras.applications import ResNet50
from tensorflow.keras.models import Model
from tensorflow.keras.optimizers import SGD
from sklearn.preprocessing import LabelBinarizer
from sklearn.model_selection import train_test_split
from sklearn.metrics import classification_report
from imutils import paths
import matplotlib.pyplot as plt
import numpy as np
import argparse
import pickle
import cv2
import os
from sklearn.metrics import confusion_matrix
from sklearn.utils.multiclass import unique_labels
import efficientnet.keras as enet
from tensorflow.keras.layers import Dense, Dropout, Activation, BatchNormalization, Flatten, Input
and this is how my model looks like
load the ResNet-50 network, ensuring the head FC layer sets are left
# off
baseModel = enet.EfficientNetB1(weights="imagenet", include_top=False, input_tensor=Input(shape=(224, 224, 3)), pooling='avg')
# Adding 2 fully-connected layers to B0.
x = baseModel.output
x = BatchNormalization()(x)
x = Dropout(0.7)(x)
x = Dense(512)(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
x = Dropout(0.5)(x)
x = Dense(512)(x)
x = BatchNormalization()(x)
x = Activation('relu')(x)
# Output layer
predictions = Dense(len(lb.classes_), activation="softmax")(x)
model = Model(inputs = baseModel.input, outputs = predictions)
# loop over all layers in the base model and freeze them so they will
# *not* be updated during the training process
for layer in baseModel.layers:
layer.trainable = False
But for the life of me I can't figure out why I am getting the below error
AttributeError Traceback (most recent call last)
<ipython-input-19-269fe6fc6f99> in <module>()
----> 1 baseModel = enet.EfficientNetB1(weights="imagenet", include_top=False, input_tensor=Input(shape=(224, 224, 3)), pooling='avg')
2
3 # Adding 2 fully-connected layers to B0.
4 x = baseModel.output
5 x = BatchNormalization()(x)
5 frames
/usr/local/lib/python3.6/dist-packages/keras/engine/base_layer.py in _collect_previous_mask(input_tensors)
1439 inbound_layer, node_index, tensor_index = x._keras_history
1440 node = inbound_layer._inbound_nodes[node_index]
-> 1441 mask = node.output_masks[tensor_index]
1442 masks.append(mask)
1443 else:
AttributeError: 'Node' object has no attribute 'output_masks'

Answer 1

The problem is the way you import the efficientnet.
You import it from the Keras package and not from the TensorFlow.Keras package.
Change your efficientnet import to
import efficientnet.tfkeras as enet

Answer 2

Not sure, but this error maybe caused by wrong TF version. Google Colab for now comes with TF 1.x by default. Try this to change the TF version and see if this resolves the issue.
try:
%tensorflow_version 2.x
except:
print("Failed to load")