## What changes were proposed in this pull request?
Add a non-intrusive button for python API documentation, which will remove ">>>" prompts and outputs of code - for easier copying of code.
For example: The below code-snippet in the document is difficult to copy due to ">>>" prompts
```
>>> l = [('Alice', 1)]
>>> spark.createDataFrame(l).collect()
[Row(_1='Alice', _2=1)]
```
Becomes this - After the copybutton in the corner of of code-block is pressed - which is easier to copy
```
l = [('Alice', 1)]
spark.createDataFrame(l).collect()
```
## File changes
Made changes to python/docs/conf.py and copybutton.js - thus only modifying sphinx frontend and no changes were made to the documentation itself- Build process for documentation remains the same.
copybutton.js -> This JS snippet was taken from the official python.org documentation site.
## How was this patch tested?
NA
Closes#24456 from sangramga/copybutton.
Authored-by: sangramga <sangramga@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
In the course of https://issues.apache.org/jira/browse/LEGAL-226 it came to light that the guidance at http://www.apache.org/dev/licensing-howto.html#permissive-deps means that permissively-licensed dependencies has a different interpretation than we (er, I) had been operating under. "pointer ... to the license within the source tree" specifically means a copy of the license within Spark's distribution, whereas at the moment, Spark's LICENSE has a pointer to the project's license in the other project's source tree.
The remedy is simply to inline all such license references (i.e. BSD/MIT licenses) or include their text in "licenses" subdirectory and point to that.
Along the way, we can also treat other BSD/MIT licenses, whose text has been inlined into LICENSE, in the same way.
The LICENSE file can continue to provide a helpful list of BSD/MIT licensed projects and a pointer to their sites. This would be over and above including license text in the distro, which is the essential thing.
Author: Sean Owen <sowen@cloudera.com>
Closes#8919 from srowen/SPARK-10833.
