restrict scopes of local variables in python

Question

When there is a long function, how to limit the scope of variables within only a section of the function? I know in many languages one can do this with {}. How to do this in python?

I am aware that a separate function for just that section will encapsulate variables to its local namespace. But for a long, linear function, many people argue that it does not make sense to write many functions (and thus names) that are only called once.

Answer 1

Generally speaking, you can't. Python only creates scopes for modules (files, generally), classes, and functions; variables can have a more limited lifetime only in a few special cases, like the target_list in a list comprehension in Python 3. There's no block-level scope like in Perl.

So, your possible workarounds are:

• Create single-use functions or classes. The function would have to be called, whereas the class would never have to be named again after its definition, because class definitions are executed immediately.
• del variables when you're done with them.

Fun fact: coming to terms with this limitation of Python is what finally got us to get rid of let in Hy , because there's no way to make it work as one would expect.