[doc] Mention with and except clauses in globals()

[andresdelfino]

Also changed "loop control target" to "target list", as that's the actual term used by for's grammar.

The long line is intentional. If the PR is approved I'll add the line breaks.

[JulienPalard]

I just tested:

>>> bar = 42
>>> def foo():
...     global bar
...     with open("/etc/hosts") as bar:
...         ...
... 
>>> foo()
>>> bar
<_io.TextIOWrapper name='/etc/hosts' mode='r' encoding='UTF-8'>

and it works, so I'd say the proposed modification is wrong?

[andresdelfino]

@JulienPalard I believe for/class/def behave exactly the same, that part of the documentation refers to global being written after those statements. Compare this:

def for_global_before():
    global bar
    for bar in []:
        ...

def for_global_after():
    for bar in []:
        ...
    global bar

for_global_before()
for_global_after()

# ----

def class_global_before():
    global bar
    class bar:
        ...

def class_global_after():
    class bar:
        ...
    global bar

class_global_before()
class_global_after()

# ----

def def_global_before():
    global bar
    def bar():
        ...

def def_global_after():
    def bar():
        ...
    global bar

def_global_before()
def_global_after()

In all cases, _before works, but _after fails. So does with "with" and "except".

[andresdelfino]

@JulienPalard I have verified for/class/def/with/except behave in the same way. These are the examples I have run:

for

Doesn't fail

def for_global_before():
    global bar
    for bar in []:
        ...

Fails

def for_global_after():
    for bar in []:
        ...
    global bar

class

Doesn't fail

def class_global_before():
    global bar
    class bar:
        ...

Fails

def class_global_after():
    class bar:
        ...
    global bar

def

Doesn't fail

def def_global_before():
    global bar
    def bar():
        ...

Fails

def def_global_after():
    def bar():
        ...
    global bar

---

with

Doesn't fail

def with_global_before():
    global bar
    with open('/etc/hosts') as bar:
        ...

Fails

def with_global_after():
    with open('/etc/hosts') as bar:
        ...
    global bar

except

Doesn't fail

def except_global_before():
    global bar
    try:
        pass
    except Exception as bar:
        pass

Fails

def except_global_after():
    try:
        pass
    except Exception as bar:
        pass
    global bar

[andresdelfino]

@JulienPalard any chance you can take a look at this? If so, please see my previous comment.

[JulienPalard]

Thanks @andresdelfino ! TIL global behave differently if placed after þ

[andresdelfino]

@JulienPalard What's "þ"? My guess is that you wrote something that GitHub decided to parse :P

[JulienPalard]

@andresdelfino it's my way to write :P

(I do it using a compose key)