python-multithreading

问题 I'm writing code using Pandas 0.18/Python 3.5 on an intel i3 (four cores). I have read this: https://www.continuum.io/content/pandas-releasing-gil I also have some work that is IO bound (parsing CSV files into dataframes). I have to do a lot of calculation that is mostly multiplying dataframes. My code is currently parallel using concurrent.futures ThreadPoolExecutor . My question is: In general, should I be using threads to run pandas jobs in parallel, or does pandas make effective use of

问题 I am trying to create 86 instances of task.py to run simultaneously. import sys import subprocess for file in range(86): subprocess.call([sys.executable,'task.py',str(file)+'in.csv',str(filen)+'out.csv']) 回答1: subprocess.call waits for command to complete. Use subprocess.Popen instead: import sys import subprocess procs = [] for i in range(86): proc = subprocess.Popen([sys.executable, 'task.py', '{}in.csv'.format(i), '{}out.csv'.format(i)]) procs.append(proc) for proc in procs: proc.wait() 来源

问题 I am trying to create 86 instances of task.py to run simultaneously. import sys import subprocess for file in range(86): subprocess.call([sys.executable,'task.py',str(file)+'in.csv',str(filen)+'out.csv']) 回答1: subprocess.call waits for command to complete. Use subprocess.Popen instead: import sys import subprocess procs = [] for i in range(86): proc = subprocess.Popen([sys.executable, 'task.py', '{}in.csv'.format(i), '{}out.csv'.format(i)]) procs.append(proc) for proc in procs: proc.wait() 来源

问题 I am trying to plot two updating plots, one is a diagram and the other one is an image captured from the camera. I get an error on this line: "current_line.set_data(y_data)" in the "update" function. The error says: "AttributeError: 'list' object has no attribute 'set_data'". Any idea why am I getting this error? If I comment out this line I will get changing images from the camera and everything except the second plot seems fine (because the second plot is not updating) but I need the second

问题 I am trying to plot two updating plots, one is a diagram and the other one is an image captured from the camera. I get an error on this line: "current_line.set_data(y_data)" in the "update" function. The error says: "AttributeError: 'list' object has no attribute 'set_data'". Any idea why am I getting this error? If I comment out this line I will get changing images from the camera and everything except the second plot seems fine (because the second plot is not updating) but I need the second

问题 I want to use multiprocessing.Pool, but multiprocessing.Pool can't abort a task after a timeout. I found solution and some modify it. from multiprocessing import util, Pool, TimeoutError from multiprocessing.dummy import Pool as ThreadPool import threading import sys from functools import partial import time def worker(y): print("worker sleep {} sec, thread: {}".format(y, threading.current_thread())) start = time.time() while True: if time.time() - start >= y: break time.sleep(0.5) # show

问题 I am having an issue with this code, when I try to run this code with two separate buttons it runs fine but when I try to use only a single button to start and stop the recording by changing its text(label) to start and stop recording the code does not work. The text of the button changes but it does not record anything. import tkinter as tk import threading import pyaudio import wave from tkinter import * import tkinter.font as font from tkinter.filedialog import asksaveasfile class App():

问题 I am aware using the traditional multiprocessing library I can declare a value and share the state between processes. https://docs.python.org/3/library/multiprocessing.html?highlight=multiprocessing#sharing-state-between-processes When using the newer concurrent.futures library how can I share state between my processes? import concurrent.futures def get_user_object(batch): # do some work counter = counter + 1 print(counter) def do_multithreading(batches): with concurrent.futures

问题 I am aware using the traditional multiprocessing library I can declare a value and share the state between processes. https://docs.python.org/3/library/multiprocessing.html?highlight=multiprocessing#sharing-state-between-processes When using the newer concurrent.futures library how can I share state between my processes? import concurrent.futures def get_user_object(batch): # do some work counter = counter + 1 print(counter) def do_multithreading(batches): with concurrent.futures

问题 I am currently working on a system that sends webhooks to multiple Discord using dhooks. This is the function used to call the function which sends the webhooks. The length of webhooks is 2 and it's a list of lists. for hook in webhooks: thread.start_new_thread(send_hook,(hook, embed, tag)) This is the send_hook function: def send_hook(hook, embed, tag): embed.set_footer(text="{} x Will".format(hook[0])) <-- This is the part where the error happens webhook = Webhook(hook[1]) webhook.send