Datasets: show_examples fails to import matplotlib.pyplot

[Flamefire]

Short description
show_examples leads to an error: "AttributeError: module 'matplotlib' has no attribute 'pyplot'"

Environment information

• Operating System: Linux
• Python version: 3.7.4
• tensorflow-datasets version: 2.0.0

Reproduction instructions

import tensorflow_datasets as tfds
datasets, info = tfds.load(name='stanford_dogs',
                               with_info=True, split='train')
tfds.show_examples(
    info, datasets, rows=3, cols=3, plot_scale=3.0, image_key=None
)

Additional context
https://github.com/tensorflow/datasets/blob/dcaa4c76905bb9eb14b4e0947d1fce15c48aea0f/tensorflow_datasets/core/visualization.py#L66 is not enough, you need to explicitly import matplotlib.pyplot, see https://stackoverflow.com/questions/14812342/matplotlib-has-no-attribute-pyplot

[Eshan-Agarwal]

@Flamefire, I also encountered this error when running locally but its work fine on colab.

[Flamefire]

There is a workaround: import matplotlib.pyplot anywhere before this. Maybe colab does this by default?

[Eshan-Agarwal]

Yes you are right it works, but we use lazy imports for importing modules so that we dont need to import them externally.

[Flamefire]

Yes, and that needs fixing, hence this bug report. I just wanted to show a workaround and an idea why colab works.

A solution could be similar to https://github.com/tensorflow/datasets/blob/dcaa4c76905bb9eb14b4e0947d1fce15c48aea0f/tensorflow_datasets/core/lazy_imports_lib.py#L101-L105 or https://github.com/tensorflow/datasets/blob/dcaa4c76905bb9eb14b4e0947d1fce15c48aea0f/tensorflow_datasets/core/lazy_imports_lib.py#L119-L122

[Eshan-Agarwal]

Yes it works fine

def matplotlib(cls):
_try_import("matplotlib.pyplot")
return _try_import("matplotlib")

Please check if it works?

[Flamefire]

It does work :+1:

[Eshan-Agarwal]

okay thanks for this bug I will send PR for fixing it

[Eshan-Agarwal]

@Flamefire why it is working on colab ?

[Flamefire]

I can't say as I don't know what colab does. For an idea see https://github.com/tensorflow/datasets/issues/1696#issuecomment-602602989