Raymond: "Since there isn't much value in reporting which iterable number has failed"

Isn't there though? If the error just points to the line with the zip, and the zip is zipping multiple similar things (especially things which won't have a traceable line of Python code associated with them to narrow it down), knowing which argument was the cause of the TypeError seems rather useful. Without it, you just know *something* being zipped was wrong, but need to manually track down which of the arguments was the problem.