pkg_resources.resource_filename is not extracting files

问题

I want to package a project that contains (and uses) template html files and distribuite it as an egg. Since I’m using tornadoweb, which requires file paths to point to html files, I can’t access the resources via stream and I really need the html files to be extracted when my program is running.

I’m having a look at setuptools and according to resource_filename docs (bold is mine):

Sometimes, it is not sufficient to access a resource in string or stream form, and a true filesystem filename is needed. In such cases, you can use this method (or module-level function) to obtain a filename for a resource. If the resource is in an archive distribution (such as a zipped egg), it will be extracted to a cache directory, and the filename within the cache will be returned. If the named resource is a directory, then all resources within that directory (including subdirectories) are also extracted. If the named resource is a C extension or “eager resource” (see the setuptools documentation for details), then all C extensions and eager resources are extracted at the same time.

Which seems exactly what I need. However this is not what happens on my machine. My setup.py contains the following line:

data_files = [('html', ['html/index.html'])]

And index.html is actually included in my egg file. When I run python3 setup.py install my project gets installed as a single zipped egg file. Unfortunately, when my program executes the following line:

html_path = resource_filename(__name__, "html")

I get the following return value:

/usr/local/lib/python3.2/dist-packages/myproj-0.1-py3.2.egg/EGG-INFO/scripts/html/

The problem is that myproj-0.1-py3.2.egg is actually a zip file so this is not a valid path.

It’s strange because if I call pkg_resources.get_cache_path(‘myproj’) I get the following path back:

/root/.python-eggs/myproj-tmp

But nothing is extracted there (yes, I’m running the program as root, but I’m just testing it).

Any idea why my html directory is not extracted?

回答1:

Found the cause of the issue. As @erykson noted I was using the wrong directory.

After replacing

html_path = resource_filename(__name__, "html")

with

html_path = resource_filename(Requirement.parse("myproj"), "html")

everything works fine.

来源：https://stackoverflow.com/questions/22381146/pkg-resources-resource-filename-is-not-extracting-files