## What changes were proposed in this pull request?
This the case when calling `SparkSession.createDataFrame` using a Pandas DataFrame that has non-str column labels.
The column name conversion logic to handle non-string or unicode in python2 is:
```
if column is not any type of string:
name = str(column)
else if column is unicode in Python 2:
name = column.encode('utf-8')
```
## How was this patch tested?
Added a new test with a Pandas DataFrame that has int column labels
Author: Bryan Cutler <cutlerb@gmail.com>
Closes#20210 from BryanCutler/python-createDataFrame-int-col-error-SPARK-23009.
e599837248