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python - 寻找主要因素的差异

问题描述

在使用 Pythonprimefac模块时 - https://pypi.org/project/primefac/

我注意到这段代码有效：

import sys
import primefac
n = 600851475143
factors = list(primefac.primefac(n))

但这不会：

import sys
import primefac
n = 19087688894909892783503691960213776632781962588843842839953893606139157282825376128877238229887486797933180624979637419997128020864299273315243907454874577263432419226852240380380880131843664800828228959920799327101817796594944161768692639537839544009100224905464911818390882192901883104039350105285757995782376058970382205463192526628231366854662473466838863987148898819243940809068605863725041711337107340279029811816555169181781669826715177100102639379572663639848699896757952171115689208069972249342540932428107175784150214806633479073061672324629925288020557720111253896992657435200329511186117042808357973613389
factors = list(primefac.primefac(n))

导致以下错误：

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\site-packages\primefac.py", line 677, in primefac
    f = multifactor(n, methods=methods, verbose=verbose)
  File "C:\Python27\lib\site-packages\primefac.py", line 596, in multifactor
    for p in procs: p.start()
  File "C:\Python27\lib\multiprocessing\process.py", line 130, in start
    self._popen = Popen(self)
  File "C:\Python27\lib\multiprocessing\forking.py", line 277, in __init__
    dump(process_obj, to_child, HIGHEST_PROTOCOL)
  File "C:\Python27\lib\multiprocessing\forking.py", line 199, in dump
    ForkingPickler(file, protocol).dump(obj)
  File "C:\Python27\lib\pickle.py", line 224, in dump
    self.save(obj)
  File "C:\Python27\lib\pickle.py", line 331, in save
    self.save_reduce(obj=obj, *rv)
  File "C:\Python27\lib\pickle.py", line 425, in save_reduce
    save(state)
  File "C:\Python27\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "C:\Python27\lib\pickle.py", line 655, in save_dict
    self._batch_setitems(obj.iteritems())
  File "C:\Python27\lib\pickle.py", line 687, in _batch_setitems
    save(v)
  File "C:\Python27\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "C:\Python27\lib\pickle.py", line 754, in save_global
    (obj, module, name))
pickle.PicklingError: Can't pickle <function factory at 0x00000000032520B8>: it's not found as primefac.factory
type(n)Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Python27\lib\multiprocessing\forking.py", line 381, in main
    self = load(from_parent)
  File "C:\Python27\lib\pickle.py", line 1384, in load
    return Unpickler(file).load()
  File "C:\Python27\lib\pickle.py", line 864, in load
    dispatch[key](self)
  File "C:\Python27\lib\pickle.py", line 886, in load_eof
    raise EOFError
EOFError

有谁知道为什么会这样？

在这两种情况下type(n)返回<type 'long'>

标签： pythonprime-factoring

解决方案

这是我的两分钱：

  • 如果您还没有，请尝试导入gmpy2 。

  • 从您链接到的项目页面：

    GNU 的因数命令不会因数大于 2^127-1

    大约是 1.7 * 10^38，比你被“倾倒”的那个数字要小得多。因此，可能（我在这里推测）该软件包存在限制，并且报告它在某些操作系统（MacOS，截至目前）上工作的人也遇到了一些“转储”错误，这是使用处理的CPython 级别的操作系统，带有一些“垃圾”内存值，导致他们相信这是有效的。

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