Below are four examples of impossible code that operates on nothing. The latter two continue silently, throwing no errors. I saw a bug sneak by because of this. I wonder if it is within the scope of Python's design to throw Exceptions in these situations? 

x = 

for x in : print("This code is never reached")

while(None): print("This code is never reached")

emptylist = []
for x in emptylist:
    if emptylist[x] == "This code is never reached":
        print("This code is never reached")
    else: print("This code is never reached")

This sort of thing would be better caught by a linter or type checker. For example, mypy with the `--warn-unreachable` option will flag the `while None:` example.

Iterating over an empty list will not currently be caught by mypy, but it's common in real code to iterate over a list that may be empty, so it would be a major compatibility break for Python to error when iterating over an empty list.

Thank you for the quick response Jelle! I do like mypy, and I will file this with them. Good luck with the migration to GitHub :)

As Jelle says, this can't be a runtime Exception.

At best mypy or a linter could make iterating over an known empty list (like a literal []) a warning, not an error as suggested by the OP. I sometimes "comment out" loops by doing something like:

for i in []: # long_list_returning_function():
    # lots of code here

I do this just to avoid re-indenting everything if I want to skip the loop during development.