ctypes dll调用在ipython中工作但不在常规python中工作 [英] ctypes dll call works in ipython but not in regular python

问题描述

注意：我的原始问题因为偏离主题而被关闭，但我重新提交了这个问题，并为任何可能遇到类似问题的人提供答案

NOTE: My original question was closed for being off-topic, but I am resubmitting this with an answer for any who might run into a similar issue

我的系统详细信息：

Windows 10 64-bit
Python 3.6 64-bit

我遗憾的是由于机密性而无法共享数据文件或dll，但我使用的是供应商提供的dll（用Delphi编写）读取二进制文件数据文件。我也无权访问源代码，也无权获得详细的编码支持。

I unfortunately cannot share data files or the dll due to confidentiality, but I am using a vendor provided dll (written in Delphi) to read binary instrument data files. I also do not have access to the source code, nor any entitlement to detailed coding support.

下面显示了一个名为filereadtest.py的示例脚本。

A sample script called filereadtest.py is shown below.

import ctypes 

binary_file = r"C:\path\to\binaryfile"
dll_file = r"C:\path\to\dll.dll"
dll = ctypes.WinDLL(dll_file)
dll.OpenDataFile.argtypes = [ctypes.c_wchar_p]
dll.OpenDataFile.restype = ctypes.c_int32
fhandle = dll.OpenDataFile(binary_file)
print(fhandle)
dll.CloseDataFile()

当使用ipython调用时，此调用成功，但是当使用常规python调用时，此调用会产生OSError：

When called with ipython, this call is successful, but when called with regular python, this call gives an OSError:

>>> ipython filereadtest.py
0

>>> python filereadtest.py
Traceback (most recent call last):
  File "filereadtest.py", line 8, in <module>
    fhandle = dll.OpenDataFile(binary_file)
OSError: [WinError 250477278] Windows Error 0xeedfade

推荐答案

IPython导入了很多库，并深埋在该导入树中，一个特定于Windows的标志导入 win32com ，其中反过来导入 pythoncom 。 pythoncom导入加载库 pythoncomXX.dll 。 （XX = 36或python版本号）。在这种情况下，dll依赖于正在加载的库。
http://timgolden.me.uk/pywin32-docs/pythoncom。 html

IPython imports a lot of libraries, and buried deep within that import tree, a windows specific flag imports win32com, which in turn imports pythoncom. The pythoncom import loads the library pythoncomXX.dll. (XX=36 or python version number). In this case the dll depends upon this library being loaded. http://timgolden.me.uk/pywin32-docs/pythoncom.html

以下脚本有效：

import ctypes 
import pythoncom  # necessary for proper function of the dll

binary_file = r"C:\path\to\binaryfile"
dll_file = r"C:\path\to\dll.dll"
dll = ctypes.WinDLL(dll_file)
dll.OpenDataFile.argtypes = [ctypes.c_wchar_p]
dll.OpenDataFile.restype = ctypes.c_int32
fhandle = dll.OpenDataFile(binary_file)
print(fhandle)
dll.CloseDataFile()

这篇关于ctypes dll调用在ipython中工作但不在常规python中工作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！