Timestamp is undefined

[snippsat]

Error:
File "testx.py", line 11
    %matplotlib inline
    ^
SyntaxError: invalid syntax

This is made to be executed in Jupyter NoteBook,you can not run with %matplotlib inline as ordinary Python script.
Also missing NSE-BSE.csv that this code load.

Do you know how to run Jupyter Notebook?
Take a look at this post for basic setup.
You can install with pip or eg use Anacona3.

There also online clould version like Microsoft Azure Notebooks and Google Colaboratory.