Python multiprocessing 共享对象的示例代码

import multiprocessing
#an empty array globally declared
answer = []
def square_numbers(mynumbers):
#for squaring array elements, a function has been used
    global answer
    #appending square numbers to a global array
    for n in mynumbers:
        answer.append(n * n)
    #print a global array for generating an answer
    print("Answer using first process: {}".format(answer))
if __name__ == "__main__":
    #input array
    mynumbers = [5,10,15]
    #new process has been created
    p = multiprocessing.Process(target=square_numbers, args=(mynumbers,))
    #process begins here
    p.start()
    #wait unless a process is completed
    p.join()
    #print a global array for generating an answer
    print("Answer using main program: {}".format(answer))

import multiprocessing
def square_data(mydata, answer, square_sum):
  #a function has been made for squaring of given data
    #appending squares of mydata to the given array
    for ix, n in enumerate(mydata):
        answer[ix] = n * n
    #sum the square values
    square_sum.value = sum(answer)
    #print array of squared values for process p
    print("Answer in process p: {}".format(answer[:]))
    # print the sum of squared values for process p
    print("Sum of squares values in process p: {}".format(square_sum.value))
if __name__ == "__main__":
    #here, we input the data
    mydata = [1,2,3]
    #an array has been created for the int data type for three integers
    answer = multiprocessing.Array('i', 3)
    #value has been created for int data type
    square_sum = multiprocessing.Value('i')
    #new process has been created
    p = multiprocessing.Process(target=square_data, args=(mydata, answer, square_sum))
    #process begins from here
    p.start()
    #wait unless the process is completed
    p.join()
    # print an array of squared values for the main program
    print("Answer in main program: {}".format(answer[:]))
    # print the sum of squared values for the main program
    print("Sum of square values in main program: {}".format(square_sum.value))