python多进程共享变量

1.可以通过multiprocessing中Value,Array传递：

from multiprocessing import Pool,Array,Value
import time
#i:int c:char f:float d:double
val1 = Value('i', 0)
val2 = Value('d', 0.0)
val3 = Value('c', b'A')
#等价于val3=Value('c',65)
array = Array('i', [0 for _ in range(20)

def func(i):
    val1 = i
    array[i] = i
    print(val1, [i for _ in array])
    time.sleep(0.1)


if __name__=='__main__':
    p=Pool(5)
    p.map(func,range(20))
    p.close()
    p.join()

2.使用Manager（推荐）中 dict，list ，Array，Value

from multiprocessing import Pool,freeze_support,Manager
import time

def func(dict):
    if dict[0]<10:
        dict[0]+=1
        time.sleep(1)
    print(id(dict),dict.values())

def func2(val):
#val+=1 出错unsupported operand type(s) for +=: 'ValueProxy' and 'int'
    #应用val.value调用值
    val.value+=1
    time.sleep(1)
    print(value)

if __name__=='__main__':
    #Manager需放在 if __name__=='__main__'下
    manager=Manager()
    a=manager.Array('i',range(20))
    d=manager.dict({0:0})
    p=Pool(5)
    p.map(func,[d]*20)
    p.close()
    p.join()
    print(d.values())