Python multithreading principles and usage examples of analysis

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import re
import urllib
import threading
import Queue
import timeit
def getHtml(url):
  html_page = (url).read()
  return html_page
# Extract URLs of images from web pages
def getUrl(html):
  pattern = r'src="(http://img.*?)"' # Regular expressions
  imgre = (pattern)
  imglist = (imgre, html) # (pattern,string) find all successful matches in string and return the value as a list
  return imglist
class getImg():
  def __init__(self, queue, thread_name=0): # Threads share a queue
    .__init__(self)
     = queue
    self.thread_name = thread_name
    () # Starting threads
  # Use queues for inter-process communication
  def run(self):
    global count
    while (True):
      imgurl = () # Call the get() method of the queue object to remove and return an item from the queue header
      (imgurl, 'E:\mnt\girls\%' % count)
      count += 1
      if ():
        break
      .task_done() # When the user thread calls task_done() to indicate that it retrieved the item and completed all the work, then the total number of unfinished tasks is reduced.
imglist = []
def main():
  global imglist
  url = "/favorite/beauty/" # The address of the page to be crawled
  html = getHtml(url)
  imglist = getUrl(html)
def main_1():
  global count
  threads = []
  count = 0
  queue = ()
  # Add all tasks to the queue
  for img in imglist:
    (img)
  # Multi-threaded crawl to the pictures
  for i in range(4):
    thread = getImg(queue, i)
    (thread)
  # Block threads until thread execution is complete
  for thread in threads:
    ()
if __name__ == '__main__':
  main()
  t = (main_1)
  print (1)

def main_1():
  global count
  threads = []
  count = 0
  queue = ()
  # Add all tasks to the queue
  for img in imglist:
    (img)
  # Multi-threaded crawl to the pictures
  for i in range(1):
    thread = getImg(queue, i)
    (thread)
  # Block threads until thread execution is complete
  for thread in threads:
    ()

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import threading
import timeit
def countdown(n):
  while n > 0:
    n -= 1
def task1():
  COUNT = 100000000
  thread1 = (target=countdown, args=(COUNT,))
  ()
  ()
def task2():
  COUNT = 100000000
  thread1 = (target=countdown, args=(COUNT // 2,))
  thread2 = (target=countdown, args=(COUNT // 2,))
  ()
  ()
  ()
  ()
if __name__ == '__main__':
  t1 = (task1)
  print "countdown in one thread ", (1)
  t2 = (task2)
  print "countdown in two thread ", (1)