Python NLP Task

I need a python application that could use the keyword extractor using any natural language processing tool to extract one, two and three words keywords from the body of a web page. The web page can be any website or an online PDF. The user must write the program such that it 'reads' the web-link from the excel sheet (input) and then 'write' the keywords in excel sheets in front of its respective web-link (output). Here is the example attachment.