The documentation of locals() mentions that:
> Free variables are returned by locals() when it is called in function blocks [...]
The term "free variable" is defined in the documentation about the execution model (https://docs.python.org/3/reference/executionmodel.html#binding-of-names):
> If a variable is used in a code block but not defined there, it is a free variable.
That definition includes global variables (and builtin ones), but these are not returned by locals(). For example compare the following:
```
x = 1
def foo():
# global x
x = 1
def bar():
print(locals())
y = x
bar()
foo()
```
If the `global x` is commented then it prints {'x': 1}, and if it is uncommented it prints {}. The same holds for names of builtins.
So the documentation of locals() could mention this in the following way (emphasis added):
> Free variables *of enclosing functions* are returned by locals() when it is called in function blocks [...]
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There is also a StackOverflow question, that describes this confusion: https://stackoverflow.com/questions/12919278/how-to-define-free-variable-in-python
By the way, would it be helpful to add the term "free variable" to the glossary (https://docs.python.org/3/glossary.html)?
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