python 多线程共享全局变量的优劣

from threading import Thread
import time

g_num = 100

def work1():
  global g_num
  g_num += 1
  print("----in work1, g_num is %d---" % g_num)

def work2():
  print("----in work2, g_num is %d---" % g_num)

def main():
  print("---线程创建之前g_num is %d---" % g_num)

  t1 = Thread(target=work1)
  t1.start()

  # 延时一会，保证t1线程中的事情做完
  time.sleep(1)

  t2 = Thread(target=work2)
  t2.start()

  time.sleep(1)
  print("---线程创建之后g_num is %d---" % g_num)

if __name__ == "__main__":
  main()

from threading import Thread
import time

def work1(nums):
  nums.append(44)
  print("----in work1---", nums)

def work2(nums):

  print("----in work2---", nums)


g_nums = [11, 22, 33]

t1 = Thread(target=work1, args=(g_nums,))
t1.start()
# 延时一会，保证t1线程中的事情做完
time.sleep(1)
t2 = Thread(target=work2, args=(g_nums,))
t2.start()