Using a copy button

The sphinx-copybutton extension just adds a small copy-to-clipboard button in the code blocks.

If the project uses both the sphinx-copybutton extension and the nbsphinx extension, then the conf.py file should have the following lines.

# -- Sphinx-copybutton options ---------------------------------------------
# Exclude copy button from appearing over notebook cell numbers by using :not()
# The default copybutton selector is `div.highlight pre`
# https://github.com/executablebooks/sphinx-copybutton/blob/master/sphinx_copybutton/__init__.py#L82
copybutton_exclude = ".linenos, .gp"
copybutton_selector = ":not(.prompt) > div.highlight pre"

The extension just modifies the normal blocks, there is no change to the directives.