Eric Schulte writes: > Soapy Smith <soapy-sm...@comcast.net> writes: > >> Hello- >> >> I am not a user of Python (yet). During a comparison of code block >> behavior between Clojure and Python, I discovered a possible Python >> error. >> >> Here is the code block: >> >> #+begin_src python :results output >> a = (1, 2, 3, 4) >> return a >> #+end_src >> >> The evaluation of this block results in this error: >> >> File "<stdin>", line 2 >> SyntaxError: 'return' outside function >> >> Could someone please comment if this is expected Python behavior? >> > > You should only use "return" like that in a python code block when you > have ":results value".
To expand briefly on that (since this can be perplexing): The need to use `return' at all when returning the value is a special quirk of Python code blocks, and does not apply to (any?) other languages. As explained on Worg, with `:results value' (the default), "Internally, the value is obtained by wrapping the code in a function definition in the external language, and evaluating that function. Therefore, code should be written as if it were the body of such a function. In particular, note that Python does not automatically return a value from a function unless a return statement is present, and so a ‘return’ statement will usually be required in Python." http://orgmode.org/manual/Results-of-evaluation.html So when using `:results output', using `return' causes an error because there is no function to return anything from. Yours, Christian
