pyinstaller and simplehttpserver on OSX vs WIN - windows

Question

I've made a simple server based on another thread here on SO: Shutting down python TCPServer by custom handler
I wrapped this up into an .exe using pyinstaller like so:
pyinstaller C:\PATH TO FILE\server.py --distpath=\PATH TO FILE\ --onedir --onefile --noconsole
This works wonderfully on Windows (currently testing on Win 7 x64). I can copy this exe to any folder and get a webserver at that location. I did it this way because I am wrapping this up into a process that would be distributed with another application. The users of this application might not have python installed and they might have a browser that blocks the types of things I would like to serve during the application process.
This should also work on osx, but when I try to wrap the same python script with pyinstaller, instead of serving up the current directory, I get a server at my /Users/Username location and not the directory from where the app was run.
My process to get this to work on both Win and OSX was to begin from the python shell and run the scripts there. This works on both platforms. If I use Terminal, cd to the directory where I want to serve files, and run the python script from there, things work fine. But any attempt I make to wrap the script into something executable leads me back to the same result of serving from /Users/Username, so I'm obviously missing something fundamental of how the wrapping is working. I am assuming it has to do with shell scripting and the script being tied to the current user?
I'd like to continue to use pyinstaller for this process since it would be the same process on Windows and OSX, but I cannot seem to get the resulting app to serve files from the directory from which it is run. Any guidance on what is happening, and how to fix it through pyinstaller (or other method) would be greatly appreciated.

Answer 1

#tallforasmurf on the pyinstaller Github pointed out that I missed something in the pyinstaller docs that is very important:
Adapting to being "frozen"
In some apps it is necessary to learn at run-time whether the app is
running "live" (from source) or "frozen" (part of a bundle). For
example, you might have a configuration file that, when running
"live", is found based on a module's file attribute. That won't
work when the code is bundled.
When your application needs access to a data file, for example a
configuration file or an icon image file, you get the path to the file
with the following code:
import sys
import os
...
if getattr(sys, 'frozen', False):
# we are running in a |PyInstaller| bundle
basedir = sys._MEIPASS
else:
# we are running in a normal Python environment
basedir = os.path.dirname(__file__)
The PyInstaller bootloader adds the attribute frozen to the sys
module. If that attribute exists, your script has been launched by the
bootloader. When that is true, sys._MEIPASS (note the underscore in
the name) contains the path to the folder containing your script and
any other files or folders bundled with it. For one-folder mode this
is the distribution folder. For one-file mode it is the temporary
folder created by the bootloader .
When your program was not started by the bootloader, the standard
Python variable file is the full path to the script now executing,
and os.path.dirname() extracts the path to the folder that contains
it.
I was able to os.chdir(basedir) after going up a few levels past the .app bundle directory and properly serve the files in the same directory as the .app bundle.