如何使用多线程更新进度条以及下载文件 [英] How to Update progress bar as well as Download File using Multi-Threading

问题描述

我正在尝试使用多线程的请求模块下载文件，同时还需要更新进度条.但是这样做时，每当我按下提交按钮时，我的 GUI 就会停止工作，并且在后台文件开始下载，只有在下载后，我的进度条才会更新并且 GUI 继续正常工作.

I'm trying to download files using the Request module using Multi threading and simultaneously need to Update a Progress bar as well. But while doing so, whenever I press submit button, my GUI stops working and in the background the files start to download and only after Downloading, my Progress bar updates and GUI continues to work Normal.

我也尝试将多线程应用到 GUI 中，以便显示下载文件的进度，但它只会在整个 Process 结束后更新进度.

I have tried to apply multi-threading to the GUI as well so that the progress of downloaded files will be displayed, but it is only updating the progress after the whole Process gets over.

from datetime import datetime
from threading import Thread
import dask.dataframe as dd
from pubsub import pub
from queue import Queue
import pandas as pd
import requests
import shutil
import sqlite3
import time
import os
import csv
import wx


class MainPage(wx.Dialog):
    def __init__(self):
        wx.Dialog.__init__(self, None, title="File Selector")

        user_sizer = wx.BoxSizer(wx.HORIZONTAL)
        user_label = wx.StaticText(self, label='Number of Threads:')
        user_sizer.Add(user_label, 0, wx.ALL | wx.CENTER, 5)
        self.threads = wx.TextCtrl(self)
        user_sizer.Add(self.threads, 5, wx.ALL, 5)

        button_sizer = wx.BoxSizer(wx.HORIZONTAL)
        file_label = wx.StaticText(self, label='Select File:')
        button_sizer.Add(file_label, 0, wx.ALL | wx.CENTER, 5)
        self.select = wx.TextCtrl(self)
        button_sizer.Add(self.select, 0, wx.ALL | wx.CENTER, 10)
        file_select = wx.Button(self, label='Browse')
        file_select.Bind(wx.EVT_BUTTON, self.file)
        button_sizer.Add(file_select, 0, wx.ALL | wx.CENTER, 5)

        link_choice_sizer = wx.BoxSizer(wx.HORIZONTAL)
        link_choice_label = wx.StaticText(self, label='Link Column:')
        link_choice_sizer.Add(link_choice_label, 0, wx.ALL | wx.CENTER, 5)
        self.link_choice = wx.TextCtrl(self)
        link_choice_sizer.Add(self.link_choice, 0, wx.ALL | wx.CENTER, 5)

        file_choice_sizer = wx.BoxSizer(wx.HORIZONTAL)
        file_choice_label = wx.StaticText(self, label='File column:')
        file_choice_sizer.Add(file_choice_label, 0, wx.ALL | wx.CENTER, 5)
        self.file_choice = wx.TextCtrl(self)
        file_choice_sizer.Add(self.file_choice, 0, wx.ALL | wx.CENTER, 5)

        submit_sizer = wx.BoxSizer(wx.HORIZONTAL)
        submit_button = wx.Button(self, label='Submit')
        submit_button.Bind(wx.EVT_BUTTON, self.process)
        submit_sizer.Add(submit_button, 0, wx.TOP, 20)

        main_box = wx.BoxSizer(wx.VERTICAL)
        main_box.Add(user_sizer, 0, wx.ALL, 3)
        main_box.Add(button_sizer, 0, wx.LEFT, 43)
        main_box.Add(link_choice_sizer, 0, wx.LEFT, 39)
        main_box.Add(file_choice_sizer, 0, wx.LEFT, 43)
        main_box.Add(submit_sizer, 0, wx.LEFT, 135)

        self.user_sizer = user_sizer
        self.button_sizer = button_sizer
        self.SetSizer(main_box)
        self.Center()


    def file(self, event):
        dialog = wx.FileDialog(None, "Choose a File:", wildcard="CSV files (*.csv)|*.csv", style=wx.DD_DEFAULT_STYLE | wx.DD_NEW_DIR_BUTTON)
        if dialog.ShowModal() == wx.ID_OK:
            print(dialog.GetPath())
            path = dialog.GetPath()
            self.select.ChangeValue(path)
            print(path)
        dialog.Destroy()


    def process(self, event):
        selected_path = self.select.GetValue()
        thread = self.threads.GetValue()
        link = self.link_choice.GetValue()
        file = self.file_choice.GetValue()
        print(thread)
        print(link)
        print(file)
        if (thread != ""):
            if (selected_path != "") :
                if (link != "") :
                    if (file != "") :
                        if (thread.isdigit()) and (link.isdigit()) and (file.isdigit()) :
                            if (int(link) != int(file)):
                                if selected_path.endswith('.csv'):
                                    self.threads.Clear()
                                    self.select.Clear()
                                    self.link_choice.Clear()
                                    self.file_choice.Clear()
                                    print("out")
                                    print(file)
                                    wx.LogMessage("File processed Sucessfully")
                                    # self.csv_processing(selected_path, thread, link, file)
                                    self.progress_show(selected_path, thread, link, file)
                                else:
                                    wx.LogError("File Extension Not Valid")
                            else:
                                wx.LogError("Both Link Column and File Column Can't be Same")
                        else:
                            wx.LogError("Please Enter Valid Number")
                    else:
                        wx.LogError("Please Enter Number in File Column")
                else:
                    wx.LogError("Please Enter Number in Link Column")
            else:
                wx.LogError("Please Select File")
        else:
            wx.LogError("Please Enter Number in Thread")

    def progress_show(self, selected_path, thread, link, file):
        pub.sendMessage('frameListener', message='show', selected_path = selected_path, thread = thread, link = link, file = file)

class Download_file():
    def download_image(self, url, file_path, data_load):
        print("In Class")
        try:
            wx.CallAfter(self.new_update, data_load)
            response = requests.get(url)
            if response.status_code == 200:
                if (response.raw) != None:
                    with open(file_path, 'wb') as out_file:
                        out_file.write(response.content)
                    del response
            else:
                print("not found")
        except requests.exceptions.RequestException as e:
            print(e)



class DownloadWorker(Thread):
    def __init__(self, queue):
        Thread.__init__(self)
        self.queue = queue

    def run(self):
        while True:
            print("In queue")
            url, file_path, data_load = self.queue.get()
            download = Download_file
            try:
                # pub.sendMessage('progress', message='show', data_load=data_load)
                # print((url))
                download.download_image(self, url, file_path, data_load)
                # wx.CallAfter(self.new_update, data_load)
                time.sleep(1)
            finally:
                self.queue.task_done()
                print("Downloaded")

    def new_update(self, data_load):
        print("upload")
        print(data_load)
        pub.sendMessage('progress', message='show', data_load=data_load)


class Progressbar(wx.Dialog):
    def __init__(self, selected_path, thread, link, file):
        wx.Dialog.__init__(self, None, title='Progess Bar',  size=(300,100))
        print("INnnn")
        progress_sizer = wx.BoxSizer(wx.HORIZONTAL)
        self.progress_bar = wx.Gauge(self, range=100, size=(250,25), style= wx.GA_HORIZONTAL)
        progress_sizer.Add(self.progress_bar, 0, wx.CENTER)
        progress_box = wx.BoxSizer(wx.VERTICAL)
        progress_box.Add(progress_sizer, wx.ALIGN_CENTRE, 25)
        print(selected_path, thread, link, file)
        self.SetSizer(progress_box)
        self.Center()
        self.Show(True)
        self.call_progress(selected_path, thread, link, file)
        pub.subscribe(self.progressListener, 'progress')
        self.Destroy()

    def call_progress(self, selected_path, thread, link, file):
        start = datetime.now()
        count = 1
        thread = int(thread)
        dask_data = dd.read_csv(selected_path, sep=',', error_bad_lines=False, quoting=csv.QUOTE_NONE, dtype="unicode")
        data_length = len(dask_data)
        data = pd.read_csv(selected_path, delimiter=',', chunksize=thread)
        count = 1
        date = str(datetime.date(datetime.now()))
        mydir = os.getcwd()
        image_dir = os.path.join(mydir, "Downloaded_Images")
        if not os.path.exists(image_dir):
            os.mkdir(image_dir)
        date_dir = os.path.join(image_dir, date)
        if not os.path.exists(date_dir):
            os.mkdir(date_dir)
        link_name =  'Link_column' + '___' + str(link)
        link_column = os.path.join(date_dir, link_name)
        if not os.path.exists(link_column):
            os.mkdir(link_column)
        queue = Queue()
        for x in range(thread):
            worker = DownloadWorker(queue)
            worker.daemon = True
            worker.start()
        thread_length = thread
        for df in data:
            data_load = round((thread_length / data_length) * 100)
            if data_load > 100:
                data_load = 100
            for i in range(thread):
                try:
                    print(df.iloc[i][int(link) - 1])
                    url = (df.iloc[i][int(link) - 1])
                    print(df.iloc[i][int(file) - 1])
                    file_name = (df.iloc[i][int(file) - 1])
                    print(count)
                    # print(data_load)
                    file_path = os.path.join(link_column, file_name)
                    queue.put((url, file_path, data_load))
                    count += 1
                except IndexError:
                    pass
            print("-------------------------")

            queue.join()
            thread_length += thread

            # data_load = round((thread / data_length) * 100)
            # if data_load > 100:
            #     data_load = 100
            # self.progress_bar.SetValue(data_load)

        # queue.join()
        print((datetime.now()) - start)

    def progressListener(self, message, data_load):
        print("listener")
        self.progress_bar.SetValue(data_load)

class MyPanel(wx.Panel):
    def __init(self, parent):
        wx.Panel.__init__(self, parent)

class MainFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None)
        MyPanel(self)
        pub.subscribe(self.myListener, 'frameListener')
        self.Center()
        dlg = MainPage()
        dlg.ShowModal()

    def myListener(self, message, selected_path, thread, link, file):
        print(selected_path, thread, link, file)
        # self.center()
        dlg = Progressbar(selected_path = selected_path, thread = thread, link = link, file = file)
        dlg.ShowModal()

def myapp():
    app = wx.App(False)
    MainFrame()
    # app.MainLoop()


if __name__ == '__main__':
    myapp()

预期的结果是应该下载文件，同时应该更新进度条.

Expected result is that the File Should be Downloaded and at the same time the Progress Bar should be Updated as well.

推荐答案

向 Mike 道歉，因为他劫持了他的骨架代码，这里是一个使用 urlretrieve 的粗略版本和一个 wxPython event 来进行更新.

With apologies to Mike for highjacking his code for a skeleton, here is a rough version using urlretrieve and a wxPython event to do the updating.

import os
import wx
import time
from threading import Thread
from urllib.request import FancyURLopener
from urllib.request import urlopen
import wx.lib.newevent

urlretrieve = FancyURLopener().retrieve
progress_event, EVT_PROGRESS_EVENT = wx.lib.newevent.NewEvent()

class DownloadThread(Thread):

    def __init__(self, parent, url, fsize):
        """Constructor"""
        Thread.__init__(self)
        self.fsize = fsize
        self.url = url
        self.parent = parent
        self.start()

    def run(self):
        local_fname = os.path.basename(self.url)
        urlretrieve(self.url, local_fname, self.reporthook)

    def reporthook(self,blocknum, blocksize, totalsize):
        readsofar = blocknum * blocksize
        if totalsize > 0:
            percent = int((readsofar / totalsize) * 100)
        else: # total size is unknown
            percent = 0
        evt = progress_event(count=percent)
        #Send back current count for the progress bar
        try:
            wx.PostEvent(self.parent, evt)
        except: # The parent frame has probably been destroyed
            pass

class MyPanel(wx.Panel):
    def __init__(self, parent):
        """Constructor"""
        wx.Panel.__init__(self, parent)

        self.lbl = wx.StaticText(self, label="Download URL:")
        self.dl_txt = wx.TextCtrl(self)
        btn = wx.Button(self, label="Download")
        self.gauge = wx.Gauge(self, -1, range=100)

        self.main_sizer = wx.BoxSizer(wx.VERTICAL)
        dl_sizer = wx.BoxSizer(wx.HORIZONTAL)

        dl_sizer.Add(self.dl_txt, 1, wx.EXPAND|wx.ALL, 5)
        dl_sizer.Add(btn, 0, wx.ALL, 5)

        self.main_sizer.Add(dl_sizer, 0, wx.EXPAND)
        self.main_sizer.Add(self.lbl, 0, wx.ALL|wx.CENTER, 5)
        self.main_sizer.Add(self.gauge, 0, wx.ALL|wx.EXPAND, 5)

        self.SetSizer(self.main_sizer)

        #Bind to the progress event issued by the thread
        self.Bind(EVT_PROGRESS_EVENT, self.OnProgress)
        btn.Bind(wx.EVT_BUTTON, self.OnDownload)

    def OnDownload(self, event):
        url = self.dl_txt.GetValue()
        self.lbl.SetLabel(os.path.basename(url))
        try:
            header = urlopen(url)
            fsize = int(header.headers['Content-Length'])
            # start thread
            d_thread = DownloadThread(self, url, fsize)
            while d_thread.isAlive():
                time.sleep(0.1)
                wx.GetApp().Yield()
                continue
            # Finished re-set
            self.dl_txt.SetValue("")
            self.lbl.SetLabel("Download URL:")
            self.gauge.SetValue(0)

        except Exception as e:
            print ("Error: ", e)

    def OnProgress(self, event):
        """"""
        self.gauge.SetValue(event.count)

class DownloaderFrame(wx.Frame):

    def __init__(self):
        """Constructor"""
        wx.Frame.__init__(self, None, title="Downloader", size=(800, 400))
        panel = MyPanel(self)
        self.Show()

if __name__ == "__main__":
    app = wx.App(False)
    frame = DownloaderFrame()
    app.MainLoop()

这篇关于如何使用多线程更新进度条以及下载文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！