On 4/20/2023 5:47 PM, Ralf M. wrote:
Hello,
when I run a script with a "normally" installed python, the directory
the script resides in is automatically added as first element to
sys.path, so that "import my_local_module" finds my_local_module.py in
the directory of the script.
However, when I run the same script with embeddable python ("Windows
embeddable package (64-bit)", download link
https://www.python.org/ftp/python/3.11.3/python-3.11.3-embed-amd64.zip)
the script directory is *not* prepended to the path, thus "import
my_local_module" gives an ImportError.
I couldn't find an option to get the "normal" behaviour. Any ideas how
to do that?
What I tried so far:
* The start-up value for sys.path seems to be defined in python311._pth.
It looks that I can add further static paths to it, but I don't know how
to make it add the script path (which can be different for different
scripts).
* Uncommenting "import site" in python311._pth doesn't help.
* It seems that I could import something else in python311._pth, but I
don't know how something imported from there could find out the path of
the script that is about to be started.
* I read the (rather short) documentation of the embeddable package and
of the site module several times but couldn't recognize a hint as to how
to solve the issue.
* I can add the following lines to every script:
import sys
script_path = __file__.rsplit("\\", 1)[0]
if script_path not in sys.path:
sys.path[0:0] = [script_path]
import my_local_modul
That works, but it's ugly, executing code between imports is frowned
upon, and it needs to be added to every script.
Does anybody have a better idea?
Any help is appreciated.
I haven't worked with embeddable python, but here are some possibilities
that came to mind, depending on how your system works -
1. If your script is started from the command line, sys.argv[0] gives
the path to the script; You could use os.path.dirname() to get its
directory. This will end up the same place as your code fragment, but
looks nicer and handles different path separators (e.g., Linux vs Windows);
2. You could write a little module that figures out the script's path
and import that first in all your scripts.
3. If you know all the directories that your scripts will be in, you
could add them all to a xx.pth file (do a search to make sure where to
put .pth files for an embeddable case).
Not executing code between imports is a guideline, but guidelines are
not laws and you can certainly deviate from them if there is a good reason.
My preference would be for 1) if at all possible. Something like this
(untested) -
import sys
import os.path
script_dir = os.path.dirname(sys.argv[0])
sys.path.insert(0, script_dir) # Use built-in method to insert
Inserting the path entry again in case it's already there is not harmful
so there's no need to check. If for some reason sys.argv is not
available, just substitute __file__. That still won't be too clunky.
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