title: threading does not speed up the process in python
body: <p>I am just learning the threading module of python, threading implementation of a test code as below takes more time compared to the sequential implementation. Am I missing an underlying concept of threading in python?</p>
  <pre><code>from time import sleep, perf_counter
  from threading import Thread
  
  def task(id):
      print(f'Starting the task {id}...')
      for i in range(1, 1000):
          for j in range(1, 1000):
              b=(i**2)/(i*j**3)
      print(f'The task {id} completed')
  
  ############## sequential ##############
  
  start_time = perf_counter()
  for n in range(1, 11):
      task(n)
  end_time = perf_counter()
  print(f'sequential took {end_time- start_time: f} second(s) to complete.')
  
  ##########E Multi-threading ##########
  
  start_time = perf_counter()
  threads = []
  for n in range(1, 11):
      t = Thread(target=task, args=(n,))
      threads.append(t)
      t.start()
  for t in threads:
      t.join()
  end_time = perf_counter()
  print(f'multi-threaded took {end_time- start_time: f} second(s) to complete.')
  </code></pre>