I am working on a Python scripts that kicks off a thread with a loop and a raw_input so that user can enter commands. After this thread starts, main program starts a loop with another raw_input so that the user can enter commands.
How can this be organized so that the commands being inputted via console goes to the correct raw_input (main thread/concurrent thread)? At the moment, all inputs in the console are going to the main thread only.
Thanks
Example
import threading
def commThread():
while True:
chatAcceptance = raw_input("User")
t1 = threading.Thread(target=commThread)
t1.start()
while True:
userInput = raw_input("\nPlease insert a command:\n")
So this can be done via lock. I did a small code example that shows how to swap between one "scope" to the other using the raw_input.
import threading
lock = threading.Lock()
def inputReader(thread, prompt):
userInput = raw_input(prompt)
print thread + " " + userInput + "\n"
return userInput
def myThread1():
global lock
while True:
lock.acquire()
print "thread 1 got the lock\n"
while True:
threadInput = inputReader("thread 1", "from thread 1\n")
if threadInput == "release":
lock.release()
print "thread 1 released the lock\n"
break
def myThread2():
global lock
while True:
lock.acquire()
print "thread 2 got the lock\n"
while True:
threadInput = inputReader("thread 2", "from thread 2\n")
if threadInput == "release":
lock.release()
print "thread 2 released the lock\n"
break
t1 = threading.Thread(target=myThread1).start()
t2 = threading.Thread(target=myThread2).start()
Related
i have a thread running on the background checking every 5 sec and print a msg after 5 secs passes.
in loop1 the msg should appear at specific point. (in this case, its above print('test')).
the thread can wait longer than 5 secs when loop1 is running (like a few sec delay is fine) but it have not to appear at the same time as loop1 is running so i put queue to for blocking.
when loop2 is running, the messsage in the multithread should appear while loop2 is running at the same time unlike loop no1.
so i didnt put queue.get in loop2 since theres no need for blocking but the problem is when going into loop3. if we go into loop3 while we are on time.sleep(5) in multithread, thats fine but if we are on print ("thread working2") in multithread, i want to make sure it waits until it does all the work in print ("thread working2") part. there are more codes there but i just put a simple print for better readability. before going into loop3. is there any way i can accomplish this? and is the method im using right now is suitable for my intention?
sorry for my bad english!
import threading
import time
from queue import Queue
queue = Queue()
queue2 = Queue()
switch = False
def func0():
while True:
global switch
global queue
global queue2
time.sleep(5)
switch = True
print ("switch on")
a = queue.get()
if a == 1:
print("thread working")
time.sleep(0.5)
print("thread working")
time.sleep(0.5)
switch = False
queue2.put(True)
if a == 2:
print("thread working2")
time.sleep(0.5)
print("thread working2")
time.sleep(0.5)
switch = False
if __name__ == "__main__":
t1 = threading.Thread(target=func0)
t1.start()
testnumber = 0
testnumber2 = 0
testnumber3 = 0
while True: #loop no.1
if switch:
queue.put(1)
queue2.get()
print ("loop1")
time.sleep(0.5)
testnumber = testnumber +1
if testnumber == 200:
break
while True: #loop no.2
if switch:
queue.put(2)
print ("loop2")
time.sleep(0.5)
testnumber2 = testnumber2 + 1
if testnumber2 == 200:
break
while True: #loop no.3
print ("loop3")
time.sleep(0.5)
testnumber3 = testnumber3 + 1
if testnumber3 == 200:
break
t1.join()
I have made a thread that is supposed to show the seconds passing. Unfortunately, when I use getstr from the curses module the whole script stops, including the thread. I have to use a thread lock to stop random characters being printed out because of overlapping orders.
Any suggestions on how to fix this or an alternative would be great!
In the below example window and window2 are already set-up...
lock = threaing.Lock()
def main_function():
#starts thread
t1 = threading.Thread(target=time_calc,args=(window2,))
t1.start()
#Gets user input
while True:
data = window1.addstr(y,x,"Type something in!")
data = window1.getstr(y,x,5)
lock.acquire()
window1.erase()
txt = "You said: "+data
window1.addstr(y,x,txt)
lock.release()
def time_calc(window2):
current_count = 0
while True:
time += 1
text = "Time Count: "+str(time)
lock.acquire()
window2.erase()
window2.addstr(y,x,text)
lock.release()
time.sleep(1)
The problem with my code
I figured out the problem with my code. You can't run a thread inside a thread for some reason and I originally had my main function called to be considered a thread. I guess I should have stated this in my question. Sorry
There is probably a way to run a thread in a thread, but this did not work for me.
My Updated Code
lock = threading.Lock()
def call_threads():
t1 = threading.Thread(target=main_function,args=(window1,))
t1.start()
t2 = threading.Thread(target=time_calc,args=(window2,))
t1.start()
def main_function(window1):
#Gets user input
while True:
data = window1.addstr(y,x,"Type something in!")
data = window1.getstr(y,x,5)
lock.acquire()
window1.erase()
txt = "You said: "+data
window1.addstr(y,x,txt)
lock.release()
def time_calc(window2):
current_count = 0
while True:
time += 1
text = "Time Count: "+str(time)
lock.acquire()
window2.erase()
window2.addstr(y,x,text)
lock.release()
time.sleep(1)
If there is anything else that may have caused this error, please comment it!
Description: now, I have done input and countdown, both of which are carried out at the same time, but I want to achieve like this:
When I don't input anything during the countdown, it will execute another function after the countdown
When I input something before the end of the countdown, the countdown will pause, and then another function will be executed
My code is as follows：
import time
from threading import Thread
def waitinput():
wait_input_str = input("Please enter your account：\n")
print(wait_input_str)
thd = Thread(target=waitinput)
thd.daemon = True
thd.start()
for i in reversed(range(1, 11)):
print("\rcountdown:{}second".format(i), end="")
time.sleep(1)
# ###########################################
You can use isAlive() method to check if your thread has terminated.
In your case:
import time
from threading import Thread
def waitinput():
wait_input_str = input("Please enter your account：\n")
print(wait_input_str)
thd = Thread(target=waitinput)
thd.daemon = True
thd.start()
for i in reversed(range(1, 11)):
if not thd.isAlive():
# Execute 2
print("\nCountdown has stopped")
break
print("\rcountdown:{}second".format(i), end="")
time.sleep(1)
if thd.isAlive():
# Execute 1
print("\nCountdown has ended")
I've made a python script that factorizes a number into its prime factors. However when dealing with big numbers i may like to have an idea to the progress of the computation. (I simplified the script)
import time, sys, threading
num = int(input("Input the number to factor: "))
factors = []
def check_progress():
but = input("Press p: ")
if but == "p":
tot = int(num**(1/2))
print("Step ", k, " of ", tot, " -- ", round(k*100/tot,5), "%", end="\r", sep="")
t = threading.Thread(target=check_progress) ?
t.daemon = True ?
t.start() ?
k = 1
while(k != int(num**(1/2))):
k = (k+1)
if num%k == 0:
factors.append(int(k))
num = num//k
k = 1
print(factors)
I'm wondering if there is a way to show the progress on demand, for example, during the loop, i press a key and it prints the progress?
How can i implement a thread of something like that in my script?
Thanks and sorry for my english
Edit:
def check_progress():
while True:
but = input("## Press return to show progress ##")
tot = int(num**(1/2))
print("Step ", k, " of ", tot, " -- ", round(k*100/tot,5), "%", sep="")
Here is one possible design:
Main thread:
create queue and thread
start the progress thread
wait user input
on input:
pop result from queue (may be None)
display it
loop
Progress thread:
do the work an put status in queue
I can provide example, but I feel you are willing to learn. Feel free to comment for help.
Edit: Full example with queue.
from time import sleep
from Queue import Queue
from threading import Thread
# Main thread:
def main():
# create queue and thread
queue = Queue()
thread = Thread(target=worker, args=(queue,))
# start the progress thread
thread.start()
# wait user input
while thread.isAlive():
raw_input('--- Press any key to show status ---')
# pop result from queue (may be None)
status = queue.get_nowait()
queue.task_done()
# display it
if status:
print 'Progress: %s%%' % status
else:
print 'No status available'
# Progress thread:
def worker(queue):
# do the work an put status in queue
# Simulate long work ...
for x in xrange(100):
# put status in queue
queue.put_nowait(x)
sleep(.5)
if __name__ == '__main__':
main()
I'm quite new to Python threading, and still can't make it working properly. I do not understand why, but threads are executed consequently and not in a parallel.
Could anyone please advice, what is incorrect in the code (I simplified it as much as I can to get it closer to the examples, but it doesn't work as expected):
import threading, time
def func1():
for j in range (0, 10):
print(str(time.ctime(time.time())) + " 1")
time.sleep(0.5)
def func2():
for j in range (0, 10):
print(str(time.ctime(time.time())) + " 2")
time.sleep(0.5)
print(str(time.ctime(time.time())) + " script started")
t1 = threading.Thread(target = func1(), name = " 1")
t2 = threading.Thread(target = func2(), name = " 2")
t1.start()
t2.start()
t1.join()
t2.join()
print (str(time.ctime(time.time())) + " over")
In console output I see that the second thread only starts when the first one is finished. I've tried to make threads daemonic, remove .join() lines, but still no luck.
I want to indicate the fact that a threading.Lock object and condition synchronization objects they define are used with the "with statement," because they support the context management protocol:
lock = threading.Lock() # After: import threading
with lock:
# critical section of code
...access shared resources...
Here, the context management machinery guarantees that the lock is automatically acquired before the block is executed and released once the block is complete, regardless of exception outcomes.
Therefore, the suggested solution above by Vincent seems to be addressing a more complex problem, one that deals with placing a lock on shared common resources, stopping any other thread that tries to access the resource in its tracks (in fact, stopping any thread that attempts to acquire the same lock). Notes: A threading.Lock has two states: locked and unlocked, and it is created in the unlocked state. In the following, for example, as only one thread can update the global variable "count":
import threading, time
count = 0
def adder(addlock): # shared lock object passed in
global count
with addlock:
count = count + 1 # auto acquire/release around stmt
time.sleep(0.5)
with addlock:
count = count + 1 # only 1 thread updating at any time
addlock = threading.Lock()
threads = []
for i in range(100):
thread = threading.Thread(target=adder, args=(addlock,))
thread.start()
threads.append(thread)
for thread in threads: thread.join()
print(count)
I'd suggest another solution using multiprocessing since your two parallel functions are basically two separate processes that don't need to access any shared resources.
from multiprocessing import Process
import time
def func1():
for j in range (0, 10):
print(str(time.ctime(time.time())) + " 1")
time.sleep(0.5)
def func2():
for j in range (0, 10):
print(str(time.ctime(time.time())) + " 2")
time.sleep(0.5)
if __name__ == '__main__':
print(str(time.ctime(time.time())) + " script started")
p1 = Process(target=func1)
p1.start()
p2 = Process(target=func2)
p2.start()
p1.join()
p2.join()
print (str(time.ctime(time.time())) + " over")
You're calling your targets (target=func1()). Instead do as follows:
t1 = threading.Thread(target=func1, name = "1")
t2 = threading.Thread(target=func2, name = "2")
EDIT: This is how you lock your prints :
import threading, time
def func1(lock):
for j in range (10):
with lock:
print(str(time.ctime(time.time())) + " 1")
time.sleep(0.5)
def func2(lock):
for j in range (10):
with lock:
print(str(time.ctime(time.time())) + " 2")
time.sleep(0.5)
lock = threading.Lock()
t1 = threading.Thread(target = func1, name = " 1", args=(lock,))
t2 = threading.Thread(target = func2, name = " 2", args=(lock,))