Python官方文档代码：Multiprocessing“；锁示例"；无法运行

我尝试运行官方Python文档中的示例代码。我在OSX上创建的virtualenv中使用PyCharm。代码失败并打印出很长的错误日志

我有其他Python程序可以正常运行，但这段代码由于Lock（）而失败。（如果我打开锁，代码运行正常。）有人能告诉我为什么会发生这种情况吗。这是从Python.org正常安装Python之后的标准Python。多谢各位

代码（完全从Python.org复制）：

错误日志：

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory

回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第126行，在
self=reduce.pickle.load（从父级）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py”，第110行，在__
self.\u semlock=\u multiprocessing.semlock.\u rebuild（*状态）
FileNotFoundError:[Errno 2]没有这样的文件或目录
回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第126行，在
self=reduce.pickle.load（从父级）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py”，第110行，在__
self.\u semlock=\u multiprocessing.semlock.\u rebuild（*状态）
FileNotFoundError:[Errno 2]没有这样的文件或目录
回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第126行，在
self=reduce.pickle.load（从父级）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py”，第110行，在__
self.\u semlock=\u multiprocessing.semlock.\u rebuild（*状态）
FileNotFoundError:[Errno 2]没有这样的文件或目录
回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第126行，在
self=reduce.pickle.load（从父级）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py”，第110行，在__
self.\u semlock=\u multiprocessing.semlock.\u rebuild（*状态）
FileNotFoundError:[Errno 2]没有这样的文件或目录
回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第126行，在
self=reduce.pickle.load（从父级）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py”，第110行，在__
self.\u semlock=\u multiprocessing.semlock.\u rebuild（*状态）
FileNotFoundError:[Errno 2]没有这样的文件或目录
回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第126行，在
self=reduce.pickle.load（从父级）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py”，第110行，在__
self.\u semlock=\u multiprocessing.semlock.\u rebuild（*状态）
FileNotFoundError:[Errno 2]没有这样的文件或目录
回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第126行，在
self=reduce.pickle.load（从父级）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py”，第110行，在__
self.\u semlock=\u multiprocessing.semlock.\u rebuild（*状态）
FileNotFoundError:[Errno 2]没有这样的文件或目录
回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第126行，在
self=reduce.pickle.load（从父级）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py”，第110行，在__
self.\u semlock=\u multiprocessing.semlock.\u rebuild（*状态）
FileNotFoundError:[Errno 2]没有这样的文件或目录
回溯（最近一次呼叫最后一次）：
文件“”，第1行，在
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py”，第116行，在spawn_main中
exitcode=_main（fd，父节点_sentinel）
文件“/Library/Frameworks/Python.framework/Versions/3.9/lib/python3
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
  File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/multiprocessing/synchronize.py", line 110, in __setstate__
    self._semlock = _multiprocessing.SemLock._rebuild(*state)
FileNotFoundError: [Errno 2] No such file or directory

from multiprocessing import Process, Lock
import time

def f(l, i):
    l.acquire()
    try:
        print('hello world', i)
    finally:
        l.release()

if __name__ == '__main__':
    lock = Lock()

    for num in range(10):
        Process(target=f, args=(lock, num)).start()

    time.sleep(1)       # <-- Adding this solves the issue on OSX