Iterate loop only on button push

wxPython Users
1

Hi,

I'm quite new to wxPython, and still trying to work things out.
I have an issue, where I have a loop that I want to iterate through,
but only +1 when a button is pushed. This is because on each
iteration, I want to go to a user input. Is this possible?

e.g.

def user_input:
    #ask user to do something
    #on button return to submit for next iteration

def submit:
    for f in files:
        # 1. do some stuff
        # 2. go to user_input

I hope this makes sense, and thanks for any help.

Tommy

2

tsenate wrote:

I'm quite new to wxPython, and still trying to work things out.
I have an issue, where I have a loop that I want to iterate through,
but only +1 when a button is pushed. This is because on each
iteration, I want to go to a user input. Is this possible?

e.g.

def user_input:
    #ask user to do something
    #on button return to submit for next iteration

def submit:
    for f in files:
        # 1. do some stuff
        # 2. go to user_input

I hope this makes sense, and thanks for any help.

You have to think about things from an event-driven point of view, which
is upside-down from traditional linear programming. Basically, you
aren't in charge. Instead, your program is just a set of functions that
the operating system calls when something interesting happens.

What that means is that you have to do your state differently. Instead
of having a nice simple loop where you wait for things, you need to
store counters in "persistent" variables, so that each time you get a
button press, you can go do the next step.

For example, based on reading between the lines in your design:

    def __init__(self):
        ...
        self.pending_file_list =

    def processOneFile(self):
        if self.pending_file_list:
            next_file = self.pending_file_list.pop(0)
            ... do some stuff ...
            ... tell user to input something ...

    def onSubmit(self,evt):
        self.pending_file_list = ...list of files to process...
        self.processOneFile()

    def onUserApproval(self,evt):
        self.processOneFile()

Do you see the philosophy? The "pending_file_list" contains the list of
work yet to be done. Each time I get a user input, I go process one
file and then exit, going back to the system to wait for the next user
event. There are many ways to tell the user "I'm waiting for you". For
example, you could have a "Continue" button that gets disabled until
processOneFile is ready for the next step.

···

--
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

3

Or, attach a generator to the panel that gets loaded on creation (or
during another event) and use the generator.next()
method during the button's event call.

Test for a stop iteration exception and disable the button when this
point is reached. Enable it once the generator is loaded again.

Josh

···

On Thu, Mar 24, 2011 at 10:09 AM, Tim Roberts <timr@probo.com> wrote:

tsenate wrote:

I'm quite new to wxPython, and still trying to work things out.
I have an issue, where I have a loop that I want to iterate through,
but only +1 when a button is pushed. This is because on each
iteration, I want to go to a user input. Is this possible?

e.g.

def user_input:
#ask user to do something
#on button return to submit for next iteration

def submit:
for f in files:
# 1. do some stuff
# 2. go to user_input

I hope this makes sense, and thanks for any help.

You have to think about things from an event-driven point of view, which
is upside-down from traditional linear programming. Basically, you
aren't in charge. Instead, your program is just a set of functions that
the operating system calls when something interesting happens.

What that means is that you have to do your state differently. Instead
of having a nice simple loop where you wait for things, you need to
store counters in "persistent" variables, so that each time you get a
button press, you can go do the next step.

For example, based on reading between the lines in your design:

def __init__(self):
...
self.pending_file_list =

def processOneFile(self):
if self.pending_file_list:
next_file = self.pending_file_list.pop(0)
... do some stuff ...
... tell user to input something ...

def onSubmit(self,evt):
self.pending_file_list = ...list of files to process...
self.processOneFile()

def onUserApproval(self,evt):
self.processOneFile()

Do you see the philosophy? The "pending_file_list" contains the list of
work yet to be done. Each time I get a user input, I go process one
file and then exit, going back to the system to wait for the next user
event. There are many ways to tell the user "I'm waiting for you". For
example, you could have a "Continue" button that gets disabled until
processOneFile is ready for the next step.

--
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

--
To unsubscribe, send email to wxPython-users+unsubscribe@googlegroups.com
or visit http://groups.google.com/group/wxPython-users?hl=en

--
Josh English
Joshua.R.English@gmail.com

4

Hi Tim and Josh,

Thanks for the help. The explanation about event driven programming
was very helpful, having not programmed for very long and mainly doing
linear programming.
Going to have to get my head around it with a few trys. Will look
into the generator as well, which looks interesting.

Thanks for all the help,

Tommy

···

On Mar 24, 10:58 pm, Josh English <joshua.r.engl...@gmail.com> wrote:

Or, attach a generator to the panel that gets loaded on creation (or
during another event) and use the generator.next()
method during the button's event call.

Test for a stop iteration exception and disable the button when this
point is reached. Enable it once the generator is loaded again.

Josh

On Thu, Mar 24, 2011 at 10:09 AM, Tim Roberts <t...@probo.com> wrote:
> tsenate wrote:
>> I'm quite new to wxPython, and still trying to work things out.
>> I have an issue, where I have a loop that I want to iterate through,
>> but only +1 when a button is pushed. This is because on each
>> iteration, I want to go to a user input. Is this possible?

>> e.g.

>> def user_input:
>> #ask user to do something
>> #on button return to submit for next iteration

>> def submit:
>> for f in files:
>> # 1. do some stuff
>> # 2. go to user_input

>> I hope this makes sense, and thanks for any help.

> You have to think about things from an event-driven point of view, which
> is upside-down from traditional linear programming. Basically, you
> aren't in charge. Instead, your program is just a set of functions that
> the operating system calls when something interesting happens.

> What that means is that you have to do your state differently. Instead
> of having a nice simple loop where you wait for things, you need to
> store counters in "persistent" variables, so that each time you get a
> button press, you can go do the next step.

> For example, based on reading between the lines in your design:

> def __init__(self):
> ...
> self.pending_file_list =

> def processOneFile(self):
> if self.pending_file_list:
> next_file = self.pending_file_list.pop(0)
> ... do some stuff ...
> ... tell user to input something ...

> def onSubmit(self,evt):
> self.pending_file_list = ...list of files to process...
> self.processOneFile()

> def onUserApproval(self,evt):
> self.processOneFile()

> Do you see the philosophy? The "pending_file_list" contains the list of
> work yet to be done. Each time I get a user input, I go process one
> file and then exit, going back to the system to wait for the next user
> event. There are many ways to tell the user "I'm waiting for you". For
> example, you could have a "Continue" button that gets disabled until
> processOneFile is ready for the next step.

> --
> Tim Roberts, t...@probo.com
> Providenza & Boekelheide, Inc.

> --
> To unsubscribe, send email to wxPython-users+unsubscribe@googlegroups.com
> or visithttp://groups.google.com/group/wxPython-users?hl=en

--
Josh English
Joshua.R.Engl...@gmail.comhttp://joshenglish.livejournal.com

5

This is a good idea. I have a few cases where this would have been a better approach than what I ended up using...

···

On 3/24/11 3:58 PM, Josh English wrote:

Or, attach a generator to the panel that gets loaded on creation (or
during another event) and use the generator.next()
method during the button's event call.

Test for a stop iteration exception and disable the button when this
point is reached. Enable it once the generator is loaded again.

--
Robin Dunn
Software Craftsman