[wyldfire]

Agreed but Python lazy-loads & parses files as packages are imported. By convention these are all at file scope and at the top of the files, so it's often confined to an initialization phase. But...sometimes developers use clever fallback behavior by catching ImportError.

So the scenario described is possible to escape simple tests, I suppose.

[marmaduke]

Doesn’t the print raise a SyntaxError not ImportError?

[wyldfire]

Yes, sorry if that was confusing -- perhaps I shouldn't have brought up ImportError. The point was that uncovering SyntaxError could possibly be as challenging as other feature tests.

    try:
        import collections
    except ImportError:
        # fallback impl of collections:
        import something_that_uses_print_statement