PEP: possibility of inline using of a symbol instead of "import"

[Chris Rebert]

On Thu, Jan 6, 2011 at 8:00 PM, Erwin Mueller <erwin.mueller at deventm.org> wrote:
> On Thursday 06 January 2011 21:23:57 Robert Kern wrote:
> > On 1/6/11 12:43 PM, Erwin Mueller wrote:
> > > On Thursday 06 January 2011 16:28:49 dmitrey wrote:
> > >> hi all,
> > >> I have th PEP (I'm not sure something like that hadn't been proposed
> > >> although):
> > >> very often in a Python file header the following lines are present,
> > >> like:
> > >> from MyModule1 import myFunc1
> > >> import MyModule2 as mm2
> > >> from MyModule3 import myFunc3 as mf3
> > >> etc
> > >>
> > >> and after several pages of code they are using somewhere, maybe only
> > >> one time, e.g.
> > >> r1 = myFunc1(...)
> > >> r2 = mm2.myFunc2(...)
> > >> r3 = mf3(...)
> > >> It makes programs less clear, you have to scroll several pages of code
> > >> in IDE to understand what it refers to.
> > >>
> > >> Regards, D.
> > >
> > > Why you have several pages of code in the first place? Don't you know
> > > that you can split your code in files? Just a suggestion.
> >
> > Modules *should* have several pages of code. *Functions* should be limited
> > to about a page of code at maximum.
>
>        I'm not quite familar with Python development, but why should modules
> be so big that the user is lost in the code?

They shouldn't, but due to Python's conciseness, the amount of code a
module can hold before it becomes unwieldy is a good bit greater than
some more verbose languages. Unlike say, Java, it is quite normal to
have several classes, functions, and constants in a single Python
module. "Several pages" is not an unreasonable upper bound for a
Python module.

> What is preventing you from
> splittin a module in several files, each file with a single responsibility?

Circular dependencies perhaps. Also, how a responsibility is defined
and what level of module granularity is most useful is a design
decision requiring skilled judgment; it's possible that
just-one-module is appropriate for Dmitrey's situation.

Cheers,
Chris
--
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