Web scraping can be done by scheduling your process. That is, if you plan to scrape at the end of the day or every hour to check for any changes in prices, this can be acheived by autmatically scheduling your process. In this way you would not have to stay in front of your computer to click the enter button to execute your scraping process.
For the basic scheduling, let's scrape price information from a major retailer. The following are basic python codes for scheduling scheduling codes .The following video would be helpful to learn basic scheduling.