bug#23731: 25.1.50; Command to break parenthesized python expression over multiple lines

[John Lee]

Wishlist

I have emacs set up to indent Python code like so (I don't actually
recall what I did to configure the position of the closing parenthesis,
but I have python-indent and tab-width set to 4):

foo(
    bar, baz
)

That works fine. However, that style in a particular program I'm working
on very often means I find myself with text like this:

some_very_long_python_function_call(an_extremely_long_name_here,
and_another_one_right_here)

At which point I'd like to be able to ask emacs to reformat that line,
or sexp if you like (the one at point, let's say), like this:

some_very_long_python_function_call(
    an_extremely_long_name_here, and_another_one_right_here
)

or sometimes like this:

some_very_long_python_function_call(
    an_extremely_long_name_here,
    and_another_one_right_here
)

Just using regular editing keys I find this a bit of a chore.

It would be really great if there were a command to do this (I guess in
python.el).


I will note that it is also fairly often the case that the reason I want
to split a function call across multiple lines is not that the line
would be too long, but that there are many arguments, so this is better:

do_something(
    foo,
    bar,
    baz,
    ham=spam
    potatoes=vegetables
)

than this:

do_something(foo, bar, baz, ham=spam potatoes=vegetables)

just because I find the former is easier to read.

Finally, in some cases the parenthesized expression to be broken over
lines is something other than a function call (e.g. an import list or
tuple -- or even a list, not strictly a parenthesized expression, but
similar).




In GNU Emacs 25.1.50.2 (x86_64-pc-linux-gnu, GTK+ Version 3.16.7)
 of 2016-04-25 built on lgw01-58
Windowing system distributor 'The X.Org Foundation', version 11.0.11702000
System Description:    Ubuntu 15.10

Configured using:
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 'CFLAGS=-g -O2 -fstack-protector-strong -Wformat
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Important settings:
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Recent messages:
[2016-06-08 13:28:20] ‘ *autoload*’ [nil 1209600]
[2016-06-08 13:28:20] ‘*Packages*’ [4890 1209600]
[2016-06-08 13:28:20] ‘*magit-diff: erp_core’ [4185 1209600]
[2016-06-08 13:28:20] ‘*magit: erp_core’ [4170 1209600]
Desktop saved in ~/.emacs.d/desktop/
Quit [4 times]
All variables and subroutines might as well have a documentation string
Mark saved where search started
Quit [2 times]
Mark saved where search started [2 times]

Load-path shadows:
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/home/john.lee/.emacs.d/elpa/seq-20151121.1017/seq hides
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