Why the WPFApp change the '.' path?

Question

I have a python project in D:/program/python/test_project/. And in the directory have a entry script named 'start.py'.It uses relative path like './pictures/icons/pic.png' to index other files in this project.

Everything works fine until I use a CSharp Project to run the python project, and it throws the path Error Exception.I print 'os.path.abspath('.')' and it refers to path 'WPFApp\bin\Debug'.The WPF is the root directory of my CSharp project.

Why does it happen?Why the '.' that represent the current directory change?

you need to use `os.path.dirname(__file__)` to get relative access to your resources. Don't trust your IDE to select the proper current directory — Jean-François Fabre, Oct 31 '19 at 09:15
If I have to change all './' to os.path.dirname(__file__) ?That's really a huge project. Is there anyway solution that I can change '.' path to os.path.dirname(__file__) at the very start? — 覃天琛, Oct 31 '19 at 09:25

score 2 · Answer 1 · answered Oct 31 '19 at 09:16

os.path.abspath('.') gives you the current working directory of your python script. When you start that script from the context of your WPF app, that's what's used as the working directory.

To find the path of your script file, have a look at this SO question: How to properly determine current script directory?.

Jean-François Fabre · Accepted Answer · 2019-10-31T09:28:40.700

When running an application through an IDE, you cannot really rely on the current directory (as opposed to when running by a .bat file for instance).

If you need resource files located in a relative way to your main script, you cannot use relative paths.

You can use __file__ which provides the full path name for the current python script, so

os.path.join(os.path.dirname(__file__),'pictures/icons/pic.png')

is the absolute path of your resource file, regardless of the current directory (which in general you cannot and should not rely on)

If for some reason you cannot change all your relative paths, you can change the current directory to the script directory at startup. Not the best solution, but it would probably work in this case:

os.chdir(os.path.abspath(os.path.dirname(__file__)))

(added abspath as if __file__ returns a filename, dirname returns an empty string and chdir fails)

Thank you so much! It does help me! – 覃天琛 Oct 31 '19 at 09:35 — 覃天琛, Oct 31 '19 at 09:35

Why the WPFApp change the '.' path?

2 Answers2