Add a warning to sheet.print_to_file [BUG]

[Tian-Jionglu]

Describe the bug
It seems that sheet.print_to_file method only works with absolute directory argument.

To Reproduce

from pycatia import catia

caa = catia()
drawing_doc = caa.active_document
sheets = drawing_rt.sheets
sheet = sheets[0]

sheet.print_to_file("./test.prn") # expected print to current directory
sheet.print_to_file("F:/temp/test.prn") # 'F:/temp/' exist.
sheet.print_to_file("F:/output/test.prn") # 'F:/output/' didn't exist. expected an error

Expected behavior
As a result, only second print_to_file (to 'F:/temp/') works as expected.
If this method performances the same in other environment, it's better to raise a warning, like "currently, this method only works with absolute directory argument. And this directory must already exist."

Desktop (please complete the following information):

• OS: Windows 10
• CATIA V5 R19
• pycatia 0.4.3

[evereux]

Added a commit to development branch. Take a look and let me know if that's what you're expecting.

Cheers.

[Tian-Jionglu]

Thank you for your quick reply.
We are almost there.
There is still problem with clause sheet.print_to_file("../test.prn"), which expected a file printed to the parent directory.
return self.drawing_sheet.PrintToFile(file_name.absolute()) seems can solve this problem. See the pull request.
When every scenario works as expected, I think no more warning is needed. 😄

[Tian-Jionglu]

Further discussion see issue #61.