On 2013.07.09 12:03, L O'Shea wrote: > Could anyone shed some light on this? I can't find mention of this anywhere > in any Python documentation or anywhere else in the code where usage_str > might be defined. In Python, you don't declare or initialize variables before using them. In the example you gave, that is where usage_str is defined. You simply assign an object to a name or attribute (which may or may not have existed previously). You can then change it to anything else you want; Python is dynamically typed, so the object you assign to it can be of any type.
Note: a class with __slots__ defined is the exception to this, but that's a bit of an advanced topic. BTW, you can play with objects in the interactive interpreter. It's a great way to quickly learn how certain things work. -- CPython 3.3.2 | Windows NT 6.2.9200 / FreeBSD 9.1 -- http://mail.python.org/mailman/listinfo/python-list
