Python 如何执行线程安全字典操作
如何使用线程安全操作dict,我想用不同的dict值(1个在操作前,1个在操作后)将dict存储到2个不同的队列中,但结果表明它们都在操作后存储dict 这是我的密码Python 如何执行线程安全字典操作,python,multithreading,python-3.x,thread-safety,python-multithreading,Python,Multithreading,Python 3.x,Thread Safety,Python Multithreading,如何使用线程安全操作dict,我想用不同的dict值(1个在操作前,1个在操作后)将dict存储到2个不同的队列中,但结果表明它们都在操作后存储dict 这是我的密码 from threading import Timer, Lock from queue import Queue q = Queue(maxsize=10000) k = Queue(maxsize=10000) k_lock = Lock() q_lock = Lock() def write_func(x): ro
from threading import Timer, Lock
from queue import Queue
q = Queue(maxsize=10000)
k = Queue(maxsize=10000)
k_lock = Lock()
q_lock = Lock()
def write_func(x):
rows = []
while not x.empty():
rows.append(x.get())
if len(rows) == 0:
return
print('A Row is {} and total A row is {}'.format(rows, len(rows)))
def write_k(x):
rows = []
while not x.empty():
rows.append(x.get())
if len(rows) == 0:
return
print('B Row is {} and total B row is {}'.format(rows, len(rows)))
def write_caller(sec=10):
write_func(q)
Timer(sec, write_caller, [sec]).start()
def k_caller(sec=1):
write_k(k)
Timer(sec, k_caller, [sec]).start()
write_caller()
k_caller()
while True:
val = {"event": "lazada"}
k.put(val)
q_val = val
with Lock():
q_val["dt"] = "2018-04-11"
q.put(q_val)
if q.qsize() >= 10:
write_func(q)
上面代码的结果如下
A Row is [{'event': 'lazada', 'dt': '2018-04-11'}, ...]
B Row is [{'event': 'lazada', 'dt': '2018-04-11'}, ...]
但是我希望B行只包含'event'而不包含'dt'。这就是我想要的
A Row is [{'event': 'lazada', 'dt': '2018-04-11'}, ...]
B Row is [{'event': 'lazada'}, ...]
当您复制字典的引用时,您不会创建变量的副本。所以q_val和val实际上是同一本字典 Python中的赋值语句不复制对象,而是在目标和对象之间创建绑定 如果要在python中复制变量,请使用
q_val = copy.copy(val)