Thanks you for writing up a proposal. There have been many proposals made, including 'EXPR as NAME', similar to yours. It even has a small section in the PEP: https://www.python.org/dev/peps/pep-0572/#alternative-spellings. It's really hard to choose between alternatives, but all things considered I have decided in favor of `NAME := EXPR` instead. Your efforts are appreciated but you would just be wasting your time if you wrote a PEP. If you're interested in helping out, would you be interested in working on the implementation of PEP 572? On Thu, Jul 5, 2018 at 12:21 PM Rin Arakaki wrote:

Hi,

I bring a strong proposal that is prematurely rejected but indeed the most likely to be accepted to our community. That is to select `as` spelling not `:=` and modify `with` and `except` statements. Here is this.

* Below is copy-pasted from my gist: https://gist.github.com/rnarkk/cdabceaedbdb498d99802a76cc08b549

# `as` assignment expression

```python # This STATEMENT(EXPR_0 as NAME_0, EXPR_1 as NAME_2, ..., EXPR_n as NAME_n)

# can always be replaced by NAME_0 = EXPR_0 NAME_1 = EXPR_1 ... NAME_n = EXPR_n STATEMENT(NAME_0, NAME_1, ..., NAME_n)

# except `import` statement since it's special from the beginning which means no `EXPR` cannot be the left hand of `as` in its statement but simply `NAME`: `import NAME_0 as NAME_1`

# This interpretation above is valid no matter how `EXPR_i` uses `NAME_j` (i > j).

# When you write EXPR as NAME_0, NAME_1

# it's interpreted as (EXPR as NAME_0), NAME_1

# TODO Should unpacking is allowed by this? EXPR as (NAME_0, NAME_1)

# `EXPR as NAME` itself can be `EXPR` and it returns just `EXPR` in `EXPR as NAME` which means you can write ((EXPR as NAME_0) as NAME_1) ... as NAME_n

# or simply like this even at the top level since it's determininable. EXPR as NAME_0 as NAME_1 ... as NAME_n

NAME_0 = EXPR as NAME_1 ... as NAME_n

# Also you can write f(x=EXPR as NAME)

# since this is valid and `EXPR as NAME` can be `EXPR`. f(x=EXPR)

# And also this is passible. if (EXPR as NAME).method(): ...

# The `EXPR` in `EXPR as NAME` is matched as long as possible which means if 0 < 1 as x: ...

# is interpreted as if (0 < 1) as x: ...

# not if 0 < (1 as x): ...

# but also `EXPR` is separated by `,` which means EXPR_0, EXPR_1 as NAME

# is interpreted as EXPR_0, (EXPR_1 as NAME)

# rather than (EXPR_0, EXPR_1) as NAME

# even when used `as` assignment expression in list comprehension, # you can apply the same rules above first by putting it to `for` loop form.

# There is no equivalence to type annotation and augmented assignment. ```

# `with` statement

- `with` statement will no longer responsible for passing returned value from `__enter__` to the right hand of `as` in its statement and merely call `__enter__` when enter the statement and `__exit__` when exit from it an - Context manager can be renamed simply to context since it will no longer be manager but context itself. Context object has status of the context and encapsulates it.

# `except` statement

- `except` statement will no longer responsible for passing instance of the right hand of `as` in its statement. - Exceptions must be instanciated and also it must be confirmed otherwise `except` statement could rewrite the class globally.

Thanks, Rin Arakaki

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