python - 如何并行循环以更改 Python 字典中的对象？

Question

这是我的问题的最小示例:

import concurrent.futures
from functools import partial

# Object class
class obj:
    def __init__(self,tup):
        self.tup = tup

# Function includes attributes in objects of class above
def new(fi,fdic):
    fdic[fi].new = 'work_'+ str(fdic[fi].tup)
    
# Dictionary full of instances of obj above    
dic = {'a':obj(1),
       'b':obj(2),
       'c':obj(3),
       'd':obj(4),
       'e':obj(5),
       'f':obj(6),
      }

partial_new = partial(new, fdic=dic)

现在我想对字典中的所有对象进行多处理(因为我实际上有太多)。
下面的代码运行。但它不“工作”，因为我实际上需要 ProcessPool (我认为？因为我想并行处理事物)。

with concurrent.futures.ThreadPoolExecutor() as executor:
    for _ in executor.map(partial_new, dic.keys()):
        pass
print(dic['b'].new)

这个不运行:

with concurrent.futures.ProcessPoolExecutor() as executor:
    for _ in executor.map(partial_new, dic.keys()):
        pass
print(dic['b'].new)

我的问题是:我如何使这项工作？
我只需要使用该函数并行修改字典中的所有对象。稍后我将保存完整的字典，但我应用的函数不返回任何内容(如果这使事情变得更容易)。

Answer 1

问题是计算新值需要很长时间吗？

def get_new_value(dictionary_item):
    key, value = dictionary_item
    return key, 'work_' + str(value.tup)

with concurrent.futures.ProcessPoolExecutor() as executor:
    for key, new_value in executor.map(get_new_value, dic.items()):
        dic[key].new = new_value

您只能有一个线程修改 dic。但是您可以将键和值传递给线程，让线程返回键和新值，然后让原始线程完成更新字典的工作。
您可能希望将块大小指定为 map=== 编辑 ===
正如所 promise 的，我的完整文件。

import concurrent.futures

# Object class
class obj:
    def __init__(self, tup):
        self.tup = tup


# Dictionary full of instances of obj above
dic = {'a': obj(1),
       'b': obj(2),
       'c': obj(3),
       'd': obj(4),
       'e': obj(5),
       'f': obj(6),
       }


def get_new_value(dictionary_item):
    key, value = dictionary_item
    return key, 'work_' + str(value.tup)

def go():
  with concurrent.futures.ProcessPoolExecutor() as executor:
    for key, new_value in executor.map(get_new_value, dic.items()):
        dic[key].new = new_value
  # Make sure it really worked!
  for key, value in dic.items():
      print(key, value.new)


if __name__ == '__main__':
    go()