DOC:https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.reindex.html#pandas.DataFrame.reindex
#### Location of the documentation

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.reindex.html#pandas.DataFrame.reindex

#### Documentation problem
Returns
DataFrame with changed index.

#### Suggested fix for documentation
fix= a NEW DataFrame instance with changed index,NOT changing old instance .
why? I thought old instance has changed index.
