Here's a quick interpretation of Python's method: Any assignment operator (compound or not) follows the same namespace rules. Scope lookups are consistent with

Here's a quick interpretation of Python's method: Any assignment operator (compound or not) follows the same namespace rules. Scope lookups are consistent within a scope, regardless of order. Any "namespaced" lookup (`x[y]` and `foo.bar`) will act inside that namespace. Non-namespaced identifiers will always assign into the nearest enclosing scope (a scope is always a named function) by default, since clobbering outer scopes - particularly globals - is dangerous. You can opt in to clobbering with `global` and `nonlocal`. If you don't ever assign to a name in the current scope, lookups will be lexical (since a local lookup cannot succeed). --- Hopefully most of these value judgements should be relatively obvious.