Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #100839

Re: Idiom for this case?

Show key headers only | View raw

KP <kai.peters@gmail.com> writes:

> Given:
>
> cfg =  {'c': ('3840', '1024'),
>        'p1': {'gpio': '1', 'id': '4', 'coord': ('0', '0', '1280', '1024')}, 
>        'p2': {'gpio': '2', 'id': '5', 'coord': ('1280', '0', '2560', '1024')},
>        'p3': {'gpio': '3', 'id': '6', 'coord': ('2560', '0', '3840', '1024')}}
>
> for config in cfg:
>     if config != 'canvas':
>         print config

Given the above data, none of the keys equal 'canvas', so the comparison
is redundant if that's the data set.

The chosen names are also confusing. It implies that each item of ‘cfg’
is a ‘config’. Can you choose names that better communicate the
semantics of that data structure?

> Is there an idiom that combines the 'for...' & the 'if..' lines into one?

This is an opportunity to learn generator expressions::

    for item in (x for x in cfg if x != canvas):
        print item

<URL:https://docs.python.org/3/reference/expressions.html#generator-expressions>

You will learn about these by working through the Python tutorial, from
beginning to end <URL:https://docs.python.org/3/tutorial/>. Don't skip
anything, and experiment with each example to understand it before
continuing.

-- 
 \      “Anyone who believes exponential growth can go on forever in a |
  `\        finite world is either a madman or an economist.” —Kenneth |
_o__)                                                         Boulding |
Ben Finney

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Idiom for this case? KP <kai.peters@gmail.com> - 2015-12-24 14:04 -0800
  Re: Idiom for this case? Ben Finney <ben+python@benfinney.id.au> - 2015-12-25 09:30 +1100
  Re: Idiom for this case? Terry Reedy <tjreedy@udel.edu> - 2015-12-24 17:47 -0500

csiph-web