How to pass parameter to a module?

[M-a-S]

I'd like to parametrize a module. That is, to set and pass
some values into the module, while it is being imported.
I tried this:

# sub_1.py -- main program
extern = "OK"
import sub_2
print sub_2.noway # prints 'no extern' :-(
# EOF

# sub_2.py -- parametrized module, parameter is the 'extern' var
try:
noway = extern
except:
noway = 'no extern'
# EOF

You can guess, it doesn't work.
How can I pass the parameter? Can I?
M-a-S

[Daniel Dittmar]

Re: How to pass parameter to a module?

M-a-S wrote:[color=blue]
> I'd like to parametrize a module. That is, to set and pass
> some values into the module, while it is being imported.
> I tried this:
>
> # sub_1.py -- main program
> extern = "OK"
> import sub_2
> print sub_2.noway # prints 'no extern' :-(
> # EOF
>
> # sub_2.py -- parametrized module, parameter is the 'extern' var
> try:
> noway = extern
> except:
> noway = 'no extern'
> # EOF
>
> You can guess, it doesn't work.
> How can I pass the parameter? Can I?[/color]

Create an additional module sub_2_parameter s:
# sub_1.py -- main program
import sub_2_parameter s
sub_2_parameter s.extern = "OK"
import sub_2

# sub_2.py -- parametrized module, parameter is the 'extern' var
import sub_2_parameter s
try:
noway = sub_2_parameter s.extern
except:
noway = 'no extern'
# EOF

Note that modules are imported only once so you cannot import sub_2 with one
set of parameters into one module and with another set of variables into
another.

Depending on your problem, it might be better to use the builtin execfile,
because you can pass a dictionary with the parameters to the call.

Daniel

[Ulrich Petri]

Re: How to pass parameter to a module?

"M-a-S" <NO-MAIL@hotmail.co m> schrieb im Newsbeitrag
news:Vwfab.2454 $9G2.2174@twist er.southeast.rr .com...[color=blue]
> I'd like to parametrize a module. That is, to set and pass
> some values into the module, while it is being imported.
> I tried this:
>
> # sub_1.py -- main program
> extern = "OK"
> import sub_2
> print sub_2.noway # prints 'no extern' :-(
> # EOF
>
> # sub_2.py -- parametrized module, parameter is the 'extern' var
> try:
> noway = extern
> except:
> noway = 'no extern'
> # EOF
>[/color]

It looks like you are using modules where you would rather use functions.
exp:
-------------------cut---------
def sub2(blah=None) :
if blah is None:
return "no extern"
else:
return blah

sub2('test')
sub2()

HTH

Ciao Ulrich

[M-a-S]

Re: How to pass parameter to a module?

I thought about the third module. It doesn't sound good.
I hoped there're some tricks with __dict__, frames and
other __...__ objects.

For now, this is what does the task:

# sub_2.py
''' The documentation will look like this:
To set the size of dictionary and search depth,
do before including (default values are shown):
import string
string.sub_2_di ctionary_size = 10 # in megabytes
string.sub_2_se arch_depth = 1000 # in nodes
string.sub_2_ma x_responce_time = 100 # seconds
'''
import string # it's used in sub_2 anyway
# parameters
try: _DICT_SZ = string.sub_2_di ctionary_size
except: _DICT_SZ = 10
try: _DEPTH = string.sub_2_se arch_depth
except: _DEPTH = 1000
try: _RTIME = string.sub_2_ma x_responce_time
except: _RTIME = 100
# now the stuff
def do_the_job():
return "Processing with dict=%d depth=%d rtime=%d" % (_DICT_SZ,_DEPT H,_RTIME)
# EOF

# sub_1.py
import string # actually, some module, which is used in sub_2
string.sub_2_di ctionary_size = 20 # megabytes
string.sub_2_se arch_depth = 5000 # nodes
# let's leave sub_2_max_respo nce_time default
import sub_2
print sub_2.do_the_jo b()
# EOF

M-a-S

"Daniel Dittmar" <daniel.dittmar @sap.com> wrote in message news:bkc62g$5k0 $1@news1.wdf.sa p-ag.de...[color=blue]
> M-a-S wrote:[color=green]
> > I'd like to parametrize a module. That is, to set and pass[/color]
>
> Create an additional module sub_2_parameter s:
> # sub_1.py -- main program
> import sub_2_parameter s
> sub_2_parameter s.extern = "OK"
> import sub_2
>
> # sub_2.py -- parametrized module, parameter is the 'extern' var
> import sub_2_parameter s
> try:
> noway = sub_2_parameter s.extern
> except:
> noway = 'no extern'
> # EOF
>
> Note that modules are imported only once so you cannot import sub_2 with one
> set of parameters into one module and with another set of variables into
> another.
>
> Depending on your problem, it might be better to use the builtin execfile,
> because you can pass a dictionary with the parameters to the call.
>
> Daniel[/color]

[Michael Peuser]

Re: How to pass parameter to a module?


"M-a-S" <NO-MAIL@hotmail.co m>
[color=blue]
> I thought about the third module. It doesn't sound good.
> I hoped there're some tricks with __dict__, frames and
> other __...__ objects.
>[/color]

Well, there are some tricks ;-)


myVariable='gre at surprise'
import x
........

"This is modul X"
import sys
print sys.modules['__main__'].myVariable


But generally the namespace of a module is ... the module.

Kindly
Michael P

[M-a-S]

Re: How to pass parameter to a module?

That's what I asked. Thanks!
M-a-S

"Michael Peuser" <mpeuser@web.de > wrote in message news:bkd0rb$qb2 $01$1@news.t-online.com...[color=blue]
>
> "M-a-S" <NO-MAIL@hotmail.co m>
>[color=green]
> > I thought about the third module. It doesn't sound good.
> > I hoped there're some tricks with __dict__, frames and
> > other __...__ objects.
> >[/color]
>
> Well, there are some tricks ;-)
>
>
> myVariable='gre at surprise'
> import x
> .......
>
> "This is modul X"
> import sys
> print sys.modules['__main__'].myVariable
>
>
> But generally the namespace of a module is ... the module.
>
> Kindly
> Michael P[/color]

[Hung Jung Lu]

Re: How to pass parameter to a module?

"M-a-S" <NO-MAIL@hotmail.co m> wrote in message news:<Vwfab.245 4$9G2.2174@twis ter.southeast.r r.com>...[color=blue]
> I'd like to parametrize a module. That is, to set and pass
> some values into the module, while it is being imported.[/color]

There are many ways.

(However, classes may fit your need better. "Passing parameters to a
module" is not a common practice, as far as I know.)

(1) Use a built-in namespace variable.

import __builtin__
__builtin__.myv ar = 3
print myvar

This is a hack. I have been screamed at for mentioning it. :)

(2) Hack your favorite (non-builtin) module. The module could be any
of the standard library modules, or your own third module.

import sys
sys.myvar = 3

(3) Use environmental variables.

import os
os.environ['myvar'] = 'hello'

You get the idea. Python has three namespaces: built-in, global, and
local. Since global and local namespaces won't go over to the other
module, you need to rely on the built-in namespace, one way or
another. How you want to structure your data (by using the built-in
namespace, a module, a class, a dictionary or any other entities that
can hold a name entry), it's entirely up to you.

Hung Jung

[M-a-S]

Re: How to pass parameter to a module?

Thank you!

"Hung Jung Lu" <hungjunglu@yah oo.com> wrote in message news:8ef9bea6.0 309182328.5c040 595@posting.goo gle.com...[color=blue]
> "M-a-S" <NO-MAIL@hotmail.co m> wrote in message news:<Vwfab.245 4$9G2.2174@twis ter.southeast.r r.com>...[color=green]
> > I'd like to parametrize a module. That is, to set and pass
> > some values into the module, while it is being imported.[/color]
>
> There are many ways.
>
> (However, classes may fit your need better. "Passing parameters to a
> module" is not a common practice, as far as I know.)
>
> (1) Use a built-in namespace variable.
>
> import __builtin__
> __builtin__.myv ar = 3
> print myvar
>
> This is a hack. I have been screamed at for mentioning it. :)
>
> (2) Hack your favorite (non-builtin) module. The module could be any
> of the standard library modules, or your own third module.
>
> import sys
> sys.myvar = 3
>
> (3) Use environmental variables.
>
> import os
> os.environ['myvar'] = 'hello'
>
> You get the idea. Python has three namespaces: built-in, global, and
> local. Since global and local namespaces won't go over to the other
> module, you need to rely on the built-in namespace, one way or
> another. How you want to structure your data (by using the built-in
> namespace, a module, a class, a dictionary or any other entities that
> can hold a name entry), it's entirely up to you.
>
> Hung Jung[/color]