[BangPypers] Favorite tips/techniques

[s|s]

This use case where one needs to keep related values together as logical
group:

Properties, getattr, setattr are quite interesting option but I prefer
collections.namedtuple

Example

EmployeeRecord = namedtuple('EmployeeRecord', 'name, age, title,
department, paygrade')
import csvfor emp in map(EmployeeRecord._make,
csv.reader(open("employees.csv", "rb"))):
    print emp.name, emp.title
import sqlite3conn = sqlite3.connect('/companydata')cursor =
conn.cursor()cursor.execute('SELECT name, age, title, department,
paygrade FROM employees')for emp in map(EmployeeRecord._make,
cursor.fetchall()):
    print emp.name, emp.title


My contribution to bag of tricks




On Tue, Sep 10, 2013 at 9:59 PM, Gopalakrishnan Subramani <
gopalakrishnan.subramani at gmail.com> wrote:

> Attributes are stylish, readable, feel native as object compared to
> dictionary. Sometimes I use setter methods to override the default
> assignments, modify getter to format the values and getter for virtual
> attributes for DSL stuffs.
>
>
> class DictObj(dict):
>     def __getattr__(self, key):
>         if key.startswith("has_"):
>             arr = key.split("_")
>             return arr[1] in self
>
>         return self[key]
>
>     def __setattr__(self, key, value):
>         self[key] = value
>
>
> od = DictObj()
>
> od.name = "Nila"
>
> print ("Has Name? ", od.has_name)
> print ("Has Age? ", od.has_age)
>
> We have this sort of implementation for functional test verification. We
> are into Industrial Automation, we deal with measurement devices like flow,
> pressure, density, etc. Each device has got  100+ attributes like tag,
> address, current value, calibration etc.
>
> Injecting 'has' and 'is' helps test engineers write unit test based on
> device property itself.
>
> if (device.is_calibration_running): # here calibration_running is a value
> read from the device or cached and is is applied for dynamic conditions.
>      ...
>
> Although it seems like magic, but certainly not a black magic, we have
> control over there.
>
> Python must have got similar stuff  like dynamic function hooks, we could
> done still better. But we are missing.
>
>
>
>
>
>
>
> On Tue, Sep 10, 2013 at 8:48 PM, BibhasD <me at bibhas.in> wrote:
>
> > I'm just curious. I faced a similar issue before while answering a
> > question about Django on StackOverflow. Django turns context variable
> > dictionaries into objects with attributes in template. So in one
> > question in SO someone posted this question. Had to answer that Django
> > doesn't really support distinguishing such keys. So when I saw the same
> > thing discussed, thought of throwing it out here. :)
> >
> > On Tuesday 10 September 2013 08:42 PM, Dhananjay Nene wrote:
> > > Ignoring classes for the moment, how likely do you think you would
> > > have a dict like that :)
> > >
> > > On a separate note if you are using primitive types, I cannot think of
> > > any scenarios, where not coercing keys to be of the same type would be
> > > considered inappropriate (except in case of reverse dicts)
> > >
> > > On Tue, Sep 10, 2013 at 3:52 PM, Me at Bibhas <me at bibhas.in> wrote:
> > >> What would happen for a dictionary like this?
> > >>
> > >>>>> d = {'1': 'foo', 1: 'bar'}
> > >>>>> d
> > >> {'1': 'foo', 1: 'bar'}
> > >>
> > >>
> > >> On Tuesday 10 September 2013 10:00 AM, Noufal Ibrahim wrote:
> > >>> Shabda Raaj <shabda at agiliq.com> writes:
> > >>>
> > >>>>
> >
> http://code.activestate.com/recipes/52308-the-simple-but-handy-collector-of-a-bunch-of-named/
> > >>>>
> > >>>> With api responses after you have parsed the json, you start doing
> > things
> > >>>> like:
> > >>>>
> > >>>> api_response["attribute"]
> > >>>>
> > >>>> I would much prefer to do
> > >>>>
> > >>>> api_response.attribute
> > >>> I generally like to use attributes instead of keys. One additional
> > >>> advantage is that I can, if necessary, later convert the attribute
> into
> > >>> a property that does more than just return a value.
> > >>>
> > >>> [...]
> > >>>
> > >>>
> > >> _______________________________________________
> > >> BangPypers mailing list
> > >> BangPypers at python.org
> > >> https://mail.python.org/mailman/listinfo/bangpypers
> > >
> > >
> >
> > _______________________________________________
> > BangPypers mailing list
> > BangPypers at python.org
> > https://mail.python.org/mailman/listinfo/bangpypers
> >
> _______________________________________________
> BangPypers mailing list
> BangPypers at python.org
> https://mail.python.org/mailman/listinfo/bangpypers
>



-- 
Supreet Sethi
Ph UK: +447859172473
Ph IN: +919811143517
Ph Skype: d_j_i_n_n
Profile: http://www.google.com/profiles/supreet.sethi
Twt: http://twitter.com/djinn