Change Text extraction is not allowed error to warning

[madhurcodes]

I was using this library for parsing a large set of files and it gave an error halfway through because it encountered such a file. Users should not have to handle this manually in a library meant for parsing PDFs.

Changes the Text extraction is not allowed error thrown to a descriptive warning.

Fixes #350

How Has This Been Tested?

I tested this on an example PDF which threw the mentioned error with the original code and gave the correct text after the change as expected. I cannot share the PDF because I don't own copyright to it.

Checklist

• I have added tests that prove my fix is effective or that my feature works
• I have added docstrings to newly created methods and classes
• I have optimized the code at least one time after creating the initial version
• I have updated the README.md or I am verified that this is not necessary
• I have updated the readthedocs documentation or I verified that this is not necessary
• I have added a consice human-readable description of the change to CHANGELOG.md

[pietermarsman]

Hi @madhurcodes,

Thanks for your work. Could you make sure that the changes are like the suggested changes in the issue:

• Set the default value for check_extractable to False.
• If check_extractable is True we throw an Error, if False we raise a warning.
• Remove the explicit arguments for check_extractable from the high_level module.

[pietermarsman]

Looks good.

Last thing: can you add a test that checks if the warning is warned and, more importantly, that the code completes without errors.

[madhurcodes]

Hey as mentioned in the PR the PDFs I have which trigger this warning are copyright protected so I can't upload them here for testing. I have tested that it raises the correct warning on my machine.

The code is really basic and it should be clear that there is no functional change so IMO it should not require a new test since the earlier error throwing code was also untested.

[pietermarsman]

I tried changing the content of an sample encrypted document, but apparently its hard to change the password of an encrypted file using only vim 😖

Should have looked at the issue earlier. An example pdf is posted by @Recursing. You could use that one. I also notices that the encrypted samples that are in the repo already are never used for testing, these can also be used.

A lot of functionality of pdfminer.six is still untested. Having a test suite for all functionality makes it easier to add code, and to change/improve implementations in the future. That's why I'm asking. I do believe that this code works as intended 😄

If you have time to add the sample pdf from the issue, please do so. Otherwise I will find some time to do it myself and then merge this. Thanks for all the efforts so far!

[pietermarsman]

Thanks @madhurcodes