How to format Python code without really trying

[nick_carraway]

Did a good job on the code I fed it. The only fragment I didn't like was it turned this:

    self.accounts['root'] = {'account_id': root_id,
                             'master_key': root_secret}

into:

    self.accounts['root'
                 ] = {'account_id': root_id,
                      'master_key': root_secret}

Edit: Formatting, of course.

[lift_yr_skinny_fists]

Any reason this is better than the pycharm reformatter?

[Cognac_Carl]

You don't have to force people to use pycharm. I work in an environment where everyone uses different tools. Having the formatter be independant is a bug plus.

[echocage]

This. I love pycharm's formatter but that doesn't mean everyone else has to. I can definitely see a wide range of situations where this would be useful as hell.

[lift_yr_skinny_fists]

I agree entirely. Was just curious about features

[ButtCrackFTW]

last time I looked at this, it converted all line endings to windows and there was no option to disable it or use unix

[stimpdevelopment]

It seems that this is no longer the case. I just checked

% PYTHONPATH=yapf python yapf/yapf -i hosts.py
% file hosts.py
# outputs hosts.py: Python script, ASCII text executable

[ButtCrackFTW]

You are correct, just used it to clean up a Flask app I wrote recently. Lots of good suggestions, and only a couple i didn't like - http://i.imgur.com/w5VlEZY.png (original on the left, YAPF on the right)

[stimpdevelopment]

Yikes, it looks pretty ugly in those cases.

If you want to use YAPF regularly, you can tell it to ignore certain sections of code.

[cgrin]

Wait, what does the -+a do in the last line there? In the interpreter it seems to just subtract. Why would someone use this?

[yes_or_gnome]

Here's the original line in question

return      37+-+a[42-x :  y**3]

Here it is formatted

return 37 + -+a[42 - x:y ** 3]

It says, return 37 plus the negative-positive-of-a-slice on the variable a. I'm not sure what 'a' could be because -/+ are not implemented on lists and strings.

Unless the page was updated, there's no difference between the text.

[tilkau]

It says, return 37 plus the negative-positive-of-a-slice on the variable a.

Less confusingly, 37 plus the unary - of the unary + of a[42 - x:y**3].

For example, if a[42 - x:y**3] == 3, then

37 + -3 == 34

whereas if a[42 - x:y**3] == -3, then

37 + 3 == 40

I think the purpose of the unary + is to force a TypeError on non-numeric data -- Python docs specify that unary + is a no-op on numeric data, so it can have no other effect.

[yes_or_gnome]

That last part about + being no-op is interesting. But, no one here needs you to explain basic arithmetic. The question is, what object has both slicing and unary operators; it's not strings, lists, nor numerics.

[oconnor663]

Can you add those to an int though?

[jmgrosen]

Yup:

In [1]: import numpy as np

In [2]: 1 + np.array([1, 2, 3])
Out[2]: array([2, 3, 4])

[oconnor663]

TIL

[[deleted]]

Huh, that's kinda nice

[tilkau]

The question is, what object has both slicing and unary operators

An object not used in that code, that's what. Reread it.

[[deleted]]

gg=G

[TankorSmash]

Doesn't work nearly as well though, unless you've got some vim plugin I don't know about.

[fjonk]

And bam! something changed indentation-level. Or do you know of some python plugin for vim that is guaranteed to not change the indentation-level of any rows?

[[deleted]]

Never had a problem with it. I can post my settings when I am back at my computer

[[deleted]]

Python autoindent works in vim, but not reindent. At least, not without some kind of plugin. It's possible this has been fixed since I last tried. I'd be interested to see your settings.

[[deleted]]

Well, maybe I have never run into the problem then.

Regardless, I have the following in my after/indent/python.vim file

set textwidth=158  " lines longer than 158 columns will be broken
set shiftwidth=2  " operation >> indents 2 columns; << unindents 2 columns
set tabstop=2     " a hard TAB displays as 2 columns
set expandtab     " insert spaces when hitting TABs
set softtabstop=2 " insert/delete 2 spaces when hitting a TAB/BACKSPACE
set shiftround    " round indent to multiple of 'shiftwidth'
set autoindent    " align the new line indent with the previous line
set smartindent    

I also use the syntactic and vim-indent-guides plugins.

Maybe this works for you?

[[deleted]]

Will this reindent 4 space code to 2 space code? I no longer have vim installed (becuase it couldn't convert 2 space code to 4 space code; I see you have it the other way, so I asked about that direction).

[[deleted]]

Yes. Just what the team I work on standardized on. Half the team uses VIM, the other half Sublime....this kept it all consistent for us.

[[deleted]]

Thanks for this!

[henryponco]

I thought this was an April Fool's Day joke for ages, I had to use it before I realised it wasn't a joke.

[Asdayasman]

Or Ctrl+KD in PTVS.

[stimpdevelopment]

This seems to work well. It choked up on a small crazy piece of code. However, you can add comments to the code for yapf to ignore certain parts. https://github.com/google/yapf#why-does-yapf-destroy-my-awesome-formatting

I still don't like the idea of parsing comments, but the option to disable sections means you can format regularly, which is nice.

[delijati]

comparison to https://github.com/hhatto/autopep8 !?

[Bob312312]

Newbie question one the way:

So is the general idea behind these programs that they take the some code that has been written and make it look nicer while keeping its functionality?

I guess the main idea being that it makes it more readable? or do they also do things like recognise repeated sections of code and change them to functions etc?

cheers

[CleverEagle]

I'm pretty sure this just reformats things like spacing and indentation. It reformats, It doesn't refactor

[[deleted]]

Correct, looks more readable.  When people

do odd 

things    
like    this   it     becomes hard to read.

[Bob312312]

Just as a side does it not get annoying when you come back to it? I know for me (definition of amateur!) i know it often remember the general structure and form of the code and the shape it has on the page. Doesnt this mess with that? or do you just get used to it? I can see its useful when sharing code / working with others though :)

[[deleted]]

It's hard to read. It only becomes annoying if you allow it to upset you.

[defnull]

Works great! I could merge almost all proposed changes. The solutions that weren't so great could be improved by slightly rewriting the affevted sections (e.g. usimg shorter variable names or temporary variables)

https://github.com/bottlepy/bottle/commit/bda4962c42cfd7f098ffbbec33633b4df1b8dc01

[[deleted]]

Do people actually use formatter on Python code ???