Hi all,
Below is a basic threading program. The basic I idea is that I have a
function which needs to be run using a queue of data. Early on I
specified my function needed to only accept basic parameters ( no
postional *args or *kwargs ) but now I am re-writing it and I want to
accept these. Is there anyway to determine what parameters are needed
by a given function and format the arguments given appropriately. My
problem is that I feel my "Kludge"section is just that - a kludge.
While it works for most cases it won't work for all (Try running this
on function4 for example...). I guess I have a problem with multiple
if statements and I think it should just look to see what parameters
are accepted and format them appropriately. Thoughts?
If I am really screwing this up - please help me get back on the right
track. I appreciate all of the help I get and it's great to learn from
the experts.
import random
import threading
import Queue
class WorkerB(threading.Thread):
def __init__(self, *args, **kwargs):
self.id = kwargs.get('id', 0)
self.requestQ = kwargs.get('requestQ', None)
self.function = kwargs.get('function', None)
threading.Thread.__init__(self, name=self.__class__.__name__
+"."+str(self.id))
def run(self):
while 1:
input = self.requestQ.get()
if input is None: break
# How do I look at the function and determine what it
requires then apply that as an input?
# -------- Start Kludge ----------
tu=dic=False
if isinstance(input, tuple):
try:
if isinstance(input[0], tuple): tu = True
elif isinstance(input[0], list): tu=True
except: pass
try:
if isinstance(input[1], dict):dic = True
except: pass
if tu and dic:
print " -Tuple and list found"
result = self.function(*input[0], **input[1])
elif tu and not dic:
print " -Tuple found"
result = self.function(*input[0])
elif isinstance(input, list):
print " -list only found"
result = self.function(*input)
else:
print " -Unknown"
result = self.function(input)
# -------- End Kludge ----------
def function1(arg1):
print arg1
def function2(*a ):
print "args", a
def function3(*a, **kw):
print "args", a
print "kwargs", kw
def function4(arg1, *a, **kw):
print arg1
print "args", a
print "kwargs", kw
def main():
lod = 2
myQ=Queue.Queue()
# A basic example
print "\n== Example 1"
for x in range(lod):myQ.put( random.random() )
myQ.put(None)
a=WorkerB(requestQ=myQ, function=function1).start()
# Throw at is some args
print "\n== Example 2"
for x in range(lod):myQ.put(["a","b","c"])
myQ.put(None)
a=WorkerB(requestQ=myQ, function=function2).start()
# Throw at it both args and kwargs
print "\n== Example 3"
for x in range(lod):myQ.put(((1,2,3),
{"input":random.random(),"loglevel":10}))
myQ.put(None)
a=WorkerB(requestQ=myQ, function=function3).start()
# Throw at it both args and kwargs
print "\n== Example 4 Does nothing!!"
for x in range(lod):myQ.put(("alpha",(1,2,3),
{"input":random.random(),"loglevel":10}))
myQ.put(None)
a=WorkerB(requestQ=myQ, function=function4).start()
if __name__ == '__main__':
main()
10  1563 
rh0dium a écrit :
Hi all,
Below is a basic threading program. The basic I idea is that I have a
function which needs to be run using a queue of data. Early on I
specified my function needed to only accept basic parameters ( no
postional *args or *kwargs ) but now I am re-writing it and I want to
accept these. Is there anyway to determine what parameters are needed
by a given function and format the arguments given appropriately.
Yes - using inspect.getargspec. I don't have example code at hand yet,
but it's not really complicated.
On 2 May 2007 07:22:07 -0700, rh0dium <st**********@gmail.comwrote:
Hi all,
Below is a basic threading program. The basic I idea is that I have a
function which needs to be run using a queue of data. Early on I
specified my function needed to only accept basic parameters ( no
postional *args or *kwargs ) but now I am re-writing it and I want to
accept these. Is there anyway to determine what parameters are needed
by a given function and format the arguments given appropriately. My
problem is that I feel my "Kludge"section is just that - a kludge.
While it works for most cases it won't work for all (Try running this
on function4 for example...). I guess I have a problem with multiple
if statements and I think it should just look to see what parameters
are accepted and format them appropriately. Thoughts?
If I am really screwing this up - please help me get back on the right
track. I appreciate all of the help I get and it's great to learn from
the experts.
import random
import threading
import Queue
class WorkerB(threading.Thread):
def __init__(self, *args, **kwargs):
self.id = kwargs.get('id', 0)
self.requestQ = kwargs.get('requestQ', None)
self.function = kwargs.get('function', None)
threading.Thread.__init__(self, name=self.__class__.__name__
+"."+str(self.id))
def run(self):
while 1:
input = self.requestQ.get()
if input is None: break
# How do I look at the function and determine what it
requires then apply that as an input?
# -------- Start Kludge ----------
tu=dic=False
if isinstance(input, tuple):
try:
if isinstance(input[0], tuple): tu = True
elif isinstance(input[0], list): tu=True
except: pass
try:
if isinstance(input[1], dict):dic = True
except: pass
if tu and dic:
print " -Tuple and list found"
result = self.function(*input[0], **input[1])
elif tu and not dic:
print " -Tuple found"
result = self.function(*input[0])
elif isinstance(input, list):
print " -list only found"
result = self.function(*input)
else:
print " -Unknown"
result = self.function(input)
# -------- End Kludge ----------
def function1(arg1):
print arg1
def function2(*a ):
print "args", a
def function3(*a, **kw):
print "args", a
print "kwargs", kw
def function4(arg1, *a, **kw):
print arg1
print "args", a
print "kwargs", kw
def main():
lod = 2
myQ=Queue.Queue()
# A basic example
print "\n== Example 1"
for x in range(lod):myQ.put( random.random() )
myQ.put(None)
a=WorkerB(requestQ=myQ, function=function1).start()
# Throw at is some args
print "\n== Example 2"
for x in range(lod):myQ.put(["a","b","c"])
myQ.put(None)
a=WorkerB(requestQ=myQ, function=function2).start()
# Throw at it both args and kwargs
print "\n== Example 3"
for x in range(lod):myQ.put(((1,2,3),
{"input":random.random(),"loglevel":10}))
myQ.put(None)
a=WorkerB(requestQ=myQ, function=function3).start()
# Throw at it both args and kwargs
print "\n== Example 4 Does nothing!!"
for x in range(lod):myQ.put(("alpha",(1,2,3),
{"input":random.random(),"loglevel":10}))
myQ.put(None)
a=WorkerB(requestQ=myQ, function=function4).start()
if __name__ == '__main__':
main()
This is far more work than you need. Push an (args, kwargs) tuple into
your arguments queue and call self.function(*args, **kwargs).
This is far more work than you need. Push an (args, kwargs) tuple into
your arguments queue and call self.function(*args, **kwargs).
No see I tried that and that won't work.
I'm assuming what you are referring to is this (effectively)
Q.put(((),{a:"foo", b:"bar}))
input = Q.get()
self.function( *input[0], **input[1])
This will obviously fail if several conditions aren't met - hence the
kludge. Am I missing something here?
rh0dium wrote:
>This is far more work than you need. Push an (args, kwargs) tuple into
your arguments queue and call self.function(*args, **kwargs).
No see I tried that and that won't work.
Won't work? How does it fail?
I'm assuming what you are referring to is this (effectively)
Q.put(((),{a:"foo", b:"bar}))
input = Q.get()
self.function( *input[0], **input[1])
This will obviously fail if several conditions aren't met - hence the
kludge. Am I missing something here?
Obviously? Conditions? What conditions?
We do things like this constantly, and in fact, it *does* work.
Please tell us how it fails, or what is unsatisfactory about it.
Gary Herron
On 2 May 2007 08:13:12 -0700, rh0dium <st**********@gmail.comwrote:
This is far more work than you need. Push an (args, kwargs) tuple into
your arguments queue and call self.function(*args, **kwargs).
No see I tried that and that won't work.
I'm assuming what you are referring to is this (effectively)
Q.put(((),{a:"foo", b:"bar}))
input = Q.get()
self.function( *input[0], **input[1])
This will obviously fail if several conditions aren't met - hence the
kludge. Am I missing something here?
Assuming that the caller correctly pushes arguments, how can this fail?
On May 2, 7:49 am, Bruno Desthuilliers <bruno.
42.desthuilli...@wtf.websiteburo.oops.comwrote:
Yes - using inspect.getargspec. I don't have example code at hand yet,
but it's not really complicated.
Viola!! Hey this works!! Now I have modified my code to do this - way
cool (still kind of a mess though)
args, varargs, varkw, defs =
inspect.getargspec(self.function)
# Deal with just some args
if varargs is None and varkw is None:
result=self.function(input)
# Deal with *args
if varkw is None and varargs is not None and len(args) >
0:
result=self.function(input[0:-1], *input[-1])
if varkw is None and varargs is not None and len(args)==0:
result=self.function(*input[0])
# Deal with *kwargs
if varkw is not None and varargs is not None and len(args)
0:
result=self.function(input[0:-2], *input[-2],
**input[-1])
if varkw is not None and varargs is not None and
len(args)==0:
result=self.function(*input[-2], **input[-1])
if varkw is not None and varargs is None and len(args) >
0:
result=self.function(input[0:-1], **input[-1])
if varkw is not None and varargs is None and len(args) ==
0:
result=self.function(**input[0])
Now this worked until I threw a function which looked like this
def func5( input1, input2, input3 )
pass
So it barfed because of this..
if varargs is None and varkw is None:
result=self.function(input)
but all of the parameters were lumped as a list so input1 contained
them all...
A small tweak turned into this..
if varargs is None and varkw is None:
if isinstance(input, tuple):
result=self.function(*input)
else:
result=self.function(input)
But now I suppose I need to do this for all of them but that will
break my other logic...
Yuck - I have to be missing something here.
On May 2, 8:25 am, Gary Herron <gher...@islandtraining.comwrote:
rh0dium wrote:
This is far more work than you need. Push an (args, kwargs) tuple into
your arguments queue and call self.function(*args, **kwargs).
No see I tried that and that won't work.
Won't work? How does it fail?I'm assuming what you are referring to is this (effectively)
Q.put(((),{a:"foo", b:"bar}))
input = Q.get()
self.function( *input[0], **input[1])
This will obviously fail if several conditions aren't met - hence the
kludge. Am I missing something here?
Obviously? Conditions? What conditions?
We do things like this constantly, and in fact, it *does* work.
Please tell us how it fails, or what is unsatisfactory about it.
Gary Herron
Good - It looks like I am the one who is clueless..
If I do this:
def funcA(input):
pass
Then I run the code
for x in range(lod):myQ.put(random.random())
myQ.put(None)
a=WorkerB(requestQ=myQ, function=funcA).start()
This will fail because there isn't an input[1]
On 2 May 2007 09:41:56 -0700, rh0dium <st**********@gmail.comwrote:
On May 2, 8:25 am, Gary Herron <gher...@islandtraining.comwrote:
rh0dium wrote:
>This is far more work than you need. Push an (args, kwargs) tuple into
>your arguments queue and call self.function(*args, **kwargs).
No see I tried that and that won't work.
Won't work? How does it fail?I'm assuming what you are referring to is this (effectively)
Q.put(((),{a:"foo", b:"bar}))
input = Q.get()
self.function( *input[0], **input[1])
This will obviously fail if several conditions aren't met - hence the
kludge. Am I missing something here?
Obviously? Conditions? What conditions?
We do things like this constantly, and in fact, it *does* work.
Please tell us how it fails, or what is unsatisfactory about it.
Gary Herron
Good - It looks like I am the one who is clueless..
If I do this:
def funcA(input):
pass
Then I run the code
for x in range(lod):myQ.put(random.random())
myQ.put(None)
a=WorkerB(requestQ=myQ, function=funcA).start()
This will fail because there isn't an input[1]
Thats because you put the wrong value into the arguments queue.
For this use case, we define the arguments queue as being a source of 2-tuples,
with an argument list and a kwargs dict. So you have to do:
for x in range(lod):
myQ.put((random.random(), {}))
(don't be afraid of indentation and newlines - I started to modify
your source to provide a working example and got frustrated
reformatting it so I could read it)
Since you've now defined the external interface for your system (pass
it a queue of argument, kwargs tuples and a callable) it's the
responsibility of the caller to correctly satisfy that interface.
On Wed, 02 May 2007 07:22:07 -0700, rh0dium wrote:
Hi all,
Below is a basic threading program. The basic I idea is that I have a
function which needs to be run using a queue of data. Early on I
specified my function needed to only accept basic parameters ( no
postional *args or *kwargs ) but now I am re-writing it and I want to
accept these. Is there anyway to determine what parameters are needed
by a given function and format the arguments given appropriately.
Is this meant to be just a programming exercise to see how clever you can
be? It's okay if it is, but if it is meant to be something useful,
well, I can't imagine ever being in a situation where I know I have
to pass arguments (say) 4, 5, "Hello", and None to a function, but not
know whether they should be positional arguments or keyword arguments.
Or, to put it another way... the usual procedure is for the developer
(that's you) to read the function API to find out what arguments the
function expects, and how it expects them, and then the developer
modifies the parameters used accordingly.
--
Steven.
In article <ma***************************************@python. org>,
Chris Mellon <ar*****@gmail.comwrote:
>On 2 May 2007 09:41:56 -0700, rh0dium <st**********@gmail.comwrote:
>On May 2, 8:25 am, Gary Herron <gher...@islandtraining.comwrote:
rh0dium wrote:
This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics
by: Lenard Lindstrom |
last post by:
I was wondering if anyone has suggested having Python determine
a method's kind from its first parameter. 'self' is a de facto
reserved word; 'cls' is a good indicator of a class method
( __new__...
|
by: svend |
last post by:
I'm messing with some code here... Lets say I have this array:
a1 = ;
And I apply slice(0) on it, to create a copy:
a2 = a1.slice(0);
But this isn't a true copy. If I go a1 = 42, and then...
|
by: Christopher W. Douglas |
last post by:
I am writing a VB.NET application in Visual Studio 2003. I have written a
method that handles several events, such as closing a form and changing the
visible status of a form. I have some code...
|
by: Andrew Dowding |
last post by:
Hi Everybody,
I have been looking at problems with my Windows Forms C# application
and it's little Jet 4 (Access) database for the last few days. The
Windows Forms app implements a facade and...
|
by: martin |
last post by:
Hi,
I am writin a function to execute stored procedures.
The function gets passed an array with the values of the parameters and if
they are input out put params.
I attach these to the command...
|
by: Alison Givens |
last post by:
....... that nobody knows the answer.
I can't imagine that I am the only one that uses parameters in CR.
So, my question again:
I have the following problem.
(VB.NET 2003 with CR)
I have a...
|
by: vbgunz |
last post by:
Hello all,
I am just learning Python and have come across something I feel might
be a bug. Please enlightenment me... The following code presents a
challenge. How in the world do you provide an...
|
by: patrin |
last post by:
Hi All,
given the source document:
<?xml version="1.0" encoding="UTF-8"?>
<root>
<child>
<test id="1" name="first child"/>
</child>
<child>
|
by: |
last post by:
I am enjoying making generalized methods to serve common needs, such as:
ImageProcessing.MakeQuickResize();
ImageProcessing.Sharpen();
FileOps.CreateYearAndMonthAndDayDirectoryBasedOnDate()...
|
by: ryjfgjl |
last post by:
In our work, we often receive Excel tables with data in the same format. If we want to analyze these data, it can be difficult to analyze them because the data is spread across multiple Excel files...
|
by: emmanuelkatto |
last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud.
Please let me know.
Thanks!
Emmanuel
|
by: BarryA |
last post by:
What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...
|
by: Sonnysonu |
last post by:
This is the data of csv file
1 2 3
1 2 3
1 2 3
1 2 3
2 3
2 3
3
the lengths should be different i have to store the data by column-wise with in the specific length.
suppose the i have to...
|
by: Hystou |
last post by:
There are some requirements for setting up RAID:
1. The motherboard and BIOS support RAID configuration.
2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...
|
by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
|
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers,...
|
by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...
|
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
| |
