# [Python 2], <s>&nbsp;20&nbsp;</s> 21 bytes

+1 thanks to dylnan (use of `\` and newline to replace space)

<!-- language-all: lang-python -->

 if\
 sorted({0})[-1]:q

**[Try it online!][TIO-jg1f9kga]**


`{0}` is a `set` containing a single element, `0`. Calling `sorted` with a `set` as the argument yields a list, which may be indexed into with `[...]`. Without `sorted` the code `({0})` would just yield the `set` and this cannot be indexed into in the same fashion, `if({0})[-1]:q` would raise a `TypeError`. Indexing in Python is 0-based and allows negative indexing from the back, hence `sorted({0})[-1]` finds the element `0`, while `sorted({0})[1]` will raise an `IndexError`, as will `sorted({})[-1]` and `sorted({0})[]` is invalid syntax. The `0` is falsey so the body of the `if`, `q`, is never executed, however if it were it would raise a `NameError` since `q` has not been defined. Since a non-empty list is truthy we cannot trim down to `if[-1]:q` either.


[Python 2]: https://docs.python.org/2/
[TIO-jg1f9kga]: https://tio.run/##K6gsycjPM/r/PzMthqs4v6gkNUWj2qBWM1rXMNaq8P9/AA "Python 2 – Try It Online"