Error when implementing tensorflow high level api - tensorflow

Question

I am trying to implement tensorflows provided high level api's, specifically the baseline classifier. However when trying to train the model, I get the following
Error:
NotFoundError (see above for traceback): Key baseline/bias not found in checkpoint
[[Node: save/RestoreV2 = RestoreV2[dtypes=[DT_FLOAT, DT_FLOAT, DT_FLOAT, DT_INT64], _device="/job:localhost/replica:0/task:0/device:CPU:0"](_arg_save/Const_0_0, save/RestoreV2/tensor_names, save/RestoreV2/shape_and_slices)]]
Code:
import tensorflow as tf
import numpy as np
from sklearn import datasets
from sklearn.model_selection import train_test_split
def digit_cross():
# Number of classes, one class for each of 10 digits.
num_classes = 10
digit = datasets.load_digits()
x = digit.data
y = digit.target
x_train, x_test, y_train, y_test = train_test_split(x, y, test_size=.3, random_state=42)
y_train_index = np.arange(y_train.size)
train_input_fn = tf.estimator.inputs.numpy_input_fn(
x={"x": np.array(x_train)},
y=np.array(y_train),
num_epochs=None,
shuffle=False)
# Build BaselineClassifier
classifier = tf.estimator.BaselineClassifier(n_classes=num_classes,
model_dir="./checkpoints_tutorial17-1/")
# Fit model.
classifier.train(train_input_fn)
digit_cross()

Answer 1

It seems that you have a checkpoint in model_dir="./checkpoints_tutorial17-1/", which is from another model and is not from a BaselineClassifier. To be specific, you have a checkpoint file and model.ckpt-* files in that folder.
As tensorflow documented:
model_dir: Directory to save model parameters, graph and etc. This can also be used to load checkpoints from the directory into a estimator to continue training a previously saved model. If PathLike object, the path will be resolved. If None, the model_dir in config will be used if set. If both are set, they must be same. If both are None, a temporary directory will be used.
Here, BaselineClassifier will first build a graph which uses baseline/bias. Then it finds out that there is a previous checkpoint in model_dir. It will try to load this checkpoint and you should see an info (if you've done tf.logging.set_verbosity(tf.logging.INFO)) saying something like
"INFO:tensorflow:Restoring parameters from .../checkpoints_tutorial17-1\model.ckpt-..."
Because this checkpoint in model_dir is not from a BaselineClassifier, it won't have baseline/bias. BaselineClassifier cannot find it and will thus throw an error.