Copy text out of a pdf file shown in pdf viewer in Chrome web browser
By appending the URL to the Google Drive Viewer service -
https://drive.google.com/viewerng/viewer?url=https://www.kevinsheppard.com/images/0/09/Python_introduction.pdf
..I was able to view the PDF & copy text from that file
You probably can't Ctrl+C because a) it's copy protected, and/or b) is a picture of some text and not actual (selectable) text.
Take a screen-shot of it, feed it through some OCR solution (example service), copy text and correct anything the OCR didn't recognize properly.