Demos 22 and 23 produce an error

[ReinierNL]

They both give essentially the same error. This is the error message from Demo 22:
Project Demo22.exe raised exception class EPyAttributeError with message 'AttributeError: module 'threading' has no attribute '_test''.

[pyscripter]

_test was defined in Python 2 threading.py module as

# Self-test code

def _test():

    class BoundedQueue(_Verbose):

        def __init__(self, limit):
            _Verbose.__init__(self)
            self.mon = RLock()
            self.rc = Condition(self.mon)
            self.wc = Condition(self.mon)
            self.limit = limit
            self.queue = deque()

        def put(self, item):
            self.mon.acquire()
            while len(self.queue) >= self.limit:
                self._note("put(%s): queue full", item)
                self.wc.wait()
            self.queue.append(item)
            self._note("put(%s): appended, length now %d",
                       item, len(self.queue))
            self.rc.notify()
            self.mon.release()

        def get(self):
            self.mon.acquire()
            while not self.queue:
                self._note("get(): queue empty")
                self.rc.wait()
            item = self.queue.popleft()
            self._note("get(): got %s, %d left", item, len(self.queue))
            self.wc.notify()
            self.mon.release()
            return item

    class ProducerThread(Thread):

        def __init__(self, queue, quota):
            Thread.__init__(self, name="Producer")
            self.queue = queue
            self.quota = quota

        def run(self):
            from random import random
            counter = 0
            while counter < self.quota:
                counter = counter + 1
                self.queue.put("%s.%d" % (self.name, counter))
                _sleep(random() * 0.00001)


    class ConsumerThread(Thread):

        def __init__(self, queue, count):
            Thread.__init__(self, name="Consumer")
            self.queue = queue
            self.count = count

        def run(self):
            while self.count > 0:
                item = self.queue.get()
                print item
                self.count = self.count - 1

    NP = 3
    QL = 4
    NI = 5

    Q = BoundedQueue(QL)
    P = []
    for i in range(NP):
        t = ProducerThread(Q, NI)
        t.name = ("Producer-%d" % (i+1))
        P.append(t)
    C = ConsumerThread(Q, NI*NP)
    for t in P:
        t.start()
        _sleep(0.000001)
    C.start()
    for t in P:
        t.join()
    C.join()

[pyscripter]

Translated the code to python 3:

from threading import *
from collections import deque
from time import sleep

def _test():

    class BoundedQueue():

        def __init__(self, limit):
            self.mon = RLock()
            self.rc = Condition(self.mon)
            self.wc = Condition(self.mon)
            self.limit = limit
            self.queue = deque()

        def put(self, item):
            self.mon.acquire()
            while len(self.queue) >= self.limit:
                self._note("put(%s): queue full", item)
                self.wc.wait()
            self.queue.append(item)
            self._note("put(%s): appended, length now %d",
                       item, len(self.queue))
            self.rc.notify()
            self.mon.release()

        def get(self):
            self.mon.acquire()
            while not self.queue:
                self._note("get(): queue empty")
                self.rc.wait()
            item = self.queue.popleft()
            self._note("get(): got %s, %d left", item, len(self.queue))
            self.wc.notify()
            self.mon.release()
            return item

        def _note(self, format, *args):
            format = format % args
            ident = get_ident()
            try:
                name = current_thread().name
            except KeyError:
                name = "<OS thread %d>" % ident
            format = "%s: %s" % (name, format)
            print(format)

    class ProducerThread(Thread):

        def __init__(self, queue, quota):
            Thread.__init__(self, name="Producer")
            self.queue = queue
            self.quota = quota

        def run(self):
            from random import random
            counter = 0
            while counter < self.quota:
                counter = counter + 1
                self.queue.put("%s.%d" % (self.name, counter))
                sleep(random() * 0.00001)


    class ConsumerThread(Thread):

        def __init__(self, queue, count):
            Thread.__init__(self, name="Consumer")
            self.queue = queue
            self.count = count

        def run(self):
            while self.count > 0:
                item = self.queue.get()
                print(item)
                self.count = self.count - 1

    NP = 3
    QL = 4
    NI = 5

    Q = BoundedQueue(QL)
    P = []
    for i in range(NP):
        t = ProducerThread(Q, NI)
        t.name = ("Producer-%d" % (i+1))
        P.append(t)
    C = ConsumerThread(Q, NI*NP)
    for t in P:
        t.start()
        sleep(0.000001)
    C.start()
    for t in P:
        t.join()
    C.join()

_test()

But we could use a simpler test.

[ReinierNL]

ok, so I tried the code above:
I've saved it in a separate file threading_test.py and modified the code in the Memo to refer to threading_test instead of threading.
That seems to work well, as long as that python file sits in the same directory as Demo23.exe.
The only thing is that the output is not shown in the app. However, I do see it as Debug Output the IDE's Events window.
For now I am okay with that, but shouldn't we add a second memo and a splitter analogous to the other examples?

[ReinierNL]

I've now also looked at Demo 22.
Apart from making the same changes as for Demo 23,
I've now also made sure we see some output.
I've added a PythonInputOutput and added a handler for its SendData event:

procedure TForm1.PythonInputOutput1SendData(Sender: TObject;
  const Data: AnsiString);
begin
{$IFDEF MSWINDOWS}
  Writeln( Data )
{$ENDIF}
{$IFDEF LINUX}
  Writeln( ErrOutput, Data );
{$ENDIF}
end;

Now the output appears nicely in a console window.

I'll make a PR for this.

[pyscripter]

Just wait a bit. I am looking into this. It should not need the PythonInputOutput

[ReinierNL]

Oh, sorry, I missed your comment. If it's not how you want it, just reject the PR.

Anyway, I'll stop for today. Leave you undisturbed in the preparations for the Webinar tomorrow.
I am looking forward to it very much.

[pyscripter]

I am not sure why (it used to work in Python 2) but

import sys
sys.stdout = sys.stderr= open('CONOUT$', 'wt')
print("Hi")  #just for testing

is needed for the printing to the console to happen. Can you try this instead of using PythonInputOutput