lxml in TPythonThread with Delphi don´t works

[Nefari0 0]

Hi!

Have a some issue - lxml in TPythonThread with Delphi don´t works but it works in OwnThreadstate with the same script

 

Code: from lxml import html

it calls the error - this module can only be loaded into one interpreter per process

 

And when I try to run Code: BeautifulSoup(html_source,"lxml")

it calls the error - FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

but in OwnThreadstate with the same script works good. 

 

Same way the Code: BeautifulSoup(html_source,"html.parser") in TPythonThread is works, but I need lxml

 

glad to any suggestions

 

Edited December 10, 2022 by Nefari0
adding info

[SwiftExpat 65]

Likely just call CoInitialize

    CoInitialize(nil);
    try
      ... your code here
    finally
      CoUninitialize();
    end;

 

Edited December 11, 2022 by SwiftExpat
Updates based on feeback

[Nefari0 0]

I'll try to understand it. Thanks

Edited December 10, 2022 by Nefari0

[David Heffernan 2345]

3 hours ago, SwiftExpat said:

Likely just call CoInitialize

    try
      CoInitialize(nil);
     ... your code here
    finally
      CoUninitialize();
    end;

 

This code is wrong. The try is always placed after the resource has been acquired. 

[SwiftExpat 65]

19 hours ago, David Heffernan said:

This code is wrong

I think I get you point, would you write it like this?

edited above based on feeback

 

Edited December 11, 2022 by SwiftExpat
remove misleading code

[David Heffernan 2345]

No. CoInitialize doesn't report errors by throwing exceptions. You are expected to check its return value. This is stated clearly in the documentation for the function which is required reading before using it. 

 

Let's leave error handling to one side for now though. The try finally pattern is like this. 

 

res := acquireResource;

try

  res.doSomething;

finally

  releaseResource(res);

end;

 

The try/finally is protecting the code *between* acquisition and release. Therefore the try must be *after* acquisition.