構造体を持たないマルチプロセッシングの印刷コマンド

Question

今日はこの投稿Multiprocessing Error with Resultsを書きました。私はクラスにいくつかの印刷コマンドを挿入

import multiprocessing 

class class1(): 
    def classfunction1(self, a): 
     self.x = a 
     print("class 1") 


class class2(): 
    def classfunction2(self, a): 
     self.y = a 
     print("class 2") 

def test(i): 
    print("I'm in the Testfunction") 
    b = i * class1.x * class2.y 

    return b 

def init(): # added 
    print("I'm in the Initfunction") 
    global class1, class2 
    class1 = class1() 
    class2 = class2() 
    x = 1 
    y = 2 
    class1.classfunction1(x) 
    class2.classfunction2(y) 

if __name__ == "__main__": 
    init() # explicit call here 
    print("This variable is callable", class1.x) 
    print("And this one is also callable", class2.y) 
    counter = [] 
    for i in range(10): 
     counter.append(i) 
    pool = multiprocessing.Pool(initializer=init, processes=4) # implicit call 
    results = pool.imap(test, counter) 
    pool.close() 
    pool.join() 
    resultslist = list(results) 
    print(resultslist) 

：

は今、私はこのスクリプトを変更しました。しかし、結果はこのような構造のない印刷、次のとおりです。私は一度だけしたいのクラスで

I'm in the Initfunction 
class 1 
class 2 
This variable is callable 1 
And this one is also callable 2 
I'm in the Initfunction 
class 1 
class 2 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Initfunction 
class 1 
class 2 
I'm in the Initfunction 
class 1 
class 2 
I'm in the Initfunction 
class 1 
class 2 
[0, 2, 4, 6, 8, 10, 12, 14, 16, 18] 

プリント...テキストのみは、私は複数（10回）したい「私はTestfunctionにいますよ」。

解決策はありますか？

Answer 1

私は（悪い）コメント（現在削除）で説明しようとしたとして、あなたは（とクラスメソッドに）init()関数にデフォルト値とオプションの引数を追加することによってそれを行うことができます。

from __future__ import print_function 
import multiprocessing 
import sys 

sys_print = print # save built-in print function before replacement is defined 

def print(*args, **kwargs): 
    """Replacement for built-in that flushes output stream after each call.""" 
    sys_print(*args, **kwargs) 
    stdout = kwargs.get('file', sys.stdout) 
    stdout.flush() # force any buffered output to be displayed 

class class1(): 
    # note addition of optional argument with default value 
    def classfunction1(self, a, notify=False): 
     self.x = a 
     if notify: print("class 1") 

class class2(): 
    # note addition of optional argument with default value 
    def classfunction2(self, a, notify=False): 
     self.y = a 
     if notify: print("class 2") 

def test(i): 
    print("I'm in the Testfunction") 
    b = i * class1.x * class2.y 

    return b 

def init(notify=False): # note addition of optional argument with default value 
    if notify: print("I'm in the Initfunction") 
    global class1, class2 
    class1 = class1() 
    class2 = class2() 
    x = 1 
    y = 2 
    class1.classfunction1(x, notify) 
    class2.classfunction2(y, notify) 

if __name__ == "__main__": 
    init(True) # override default arg in this explicit call 
    print("This variable is callable", class1.x) 
    print("And this one is also callable", class2.y) 
    counter = list(range(10)) 
    pool = multiprocessing.Pool(initializer=init, processes=4) # implicit calls 
    results = pool.imap(test, counter) 
    pool.close() 
    pool.join() 
    resultslist = list(results) 
    print(resultslist) 

を

出力：

I'm in the Initfunction 
class 1 
class 2 
This variable is callable 1 
And this one is also callable 2 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
I'm in the Testfunction 
[0, 2, 4, 6, 8, 10, 12, 14, 16, 18]