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Finding Python script home folder

curtvprice

Often we have scripts that require a home folder location for the script to locate related files -- for example, layer files, data distributed with the tool that it uses, etc. Here are some methods to find that location.

os.path.dirname(sys.argv[0]) or os.path.dirname(__file__).

Both these locations find the path of the currently running Python script file.

Usually, __file__ is the best choice.
See: Difference between __file__ and sys.argv[0] (StackOverflow)

Toolbox (.tbx) validation code

In .tbx script tool validation code, sys.argv[0] returns an empty string, but __file__ will be the path to the function packed in a string like this: u'C:\\test\\Toolbox.tbx#Script_z.InitializeParameters.py'

In this case, the location of the tbx would be: os.path.dirname(__file__)

ModelBuilder tbx location

The ModelBuilder tbx location can be found using os.path.realpath and the Calculate Value tool with this code block:

<SPAN class="comment token"># Call with expression: home()</SPAN>
<SPAN class="keyword token">import</SPAN> os
<SPAN class="keyword token">def</SPAN> <SPAN class="token function">home</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp; <SPAN class="keyword token">return</SPAN> os<SPAN class="punctuation token">.</SPAN>path<SPAN class="punctuation token">.</SPAN>realpath<SPAN class="punctuation token">(</SPAN><SPAN class="string token">"."</SPAN><SPAN class="punctuation token">)</SPAN>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Map document location ("Home folder" in ArcMap or Pro)

Some script tools (always run from ArcMap or Pro) may need to locate data relative to the .mxd or .aprx location:

<SPAN class="comment token"># ArcMap</SPAN>
here <SPAN class="operator token">=</SPAN> os<SPAN class="punctuation token">.</SPAN>path<SPAN class="punctuation token">.</SPAN>dirname<SPAN class="punctuation token">(</SPAN>arcpy<SPAN class="punctuation token">.</SPAN>mapping<SPAN class="punctuation token">.</SPAN>MapDocument<SPAN class="punctuation token">(</SPAN><SPAN class="string token">"CURRENT"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN>filePath‍<SPAN class="punctuation token">)</SPAN>‍‍‍‍‍
<SPAN class="comment token"># ArcGIS Pro</SPAN>
here <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>mp<SPAN class="punctuation token">.</SPAN>ArcGISProject<SPAN class="punctuation token">(</SPAN><SPAN class="string token">"CURRENT"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN>filePath‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

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Comments

curtvprice

I guess as far as I know I've never run a script in this way, which I still don't follow. Maybe because have only used windows and unix??

DanPatterson_Retired

To quote you...

os.path.dirname(sys.argv[0]) or os.path.dirname(__file__).
Both these locations find the path of the currently running Python script file.
Usually, __file__ is the best choice.

__file__ doesn't exist for a currently running script unless it is imported..., was my point... see below

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> sys<SPAN class="punctuation token">.</SPAN>argv<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="string token">'/private/var/mobile/Containers/Shared/AppGroup/A9DDA80F-9432-45DA-B931-2E9386579AE6/Pythonista3/Documents/Python_3_scripts/np/ein_geom.py'</SPAN>

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> dir<SPAN class="punctuation token">(</SPAN>ein_geom<SPAN class="punctuation token">)</SPAN>
Traceback <SPAN class="punctuation token">(</SPAN>most recent call last<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp; File <SPAN class="string token">"<string>"</SPAN><SPAN class="punctuation token">,</SPAN> line <SPAN class="number token">1</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="keyword token">in</SPAN> <SPAN class="operator token"><</SPAN>module<SPAN class="operator token">></SPAN>
NameError<SPAN class="punctuation token">:</SPAN> name <SPAN class="string token">'ein_geom'</SPAN> <SPAN class="keyword token">is</SPAN> <SPAN class="operator token">not</SPAN> defined

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> <SPAN class="keyword token">import</SPAN> ein_geom

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> dir<SPAN class="punctuation token">(</SPAN>ein_geom<SPAN class="punctuation token">)</SPAN>

<SPAN class="punctuation token">[</SPAN><SPAN class="string token">'__all__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'__builtins__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'__cached__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'__doc__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'__file__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'__loader__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'__name__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'__package__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'__spec__'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'_data'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'area_demo'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'art'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'e_area'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'e_leng'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'ft'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'inspect'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'leng_demo'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'main'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'np'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'poly2pnts'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'script'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'sys'</SPAN><SPAN class="punctuation token">]</SPAN>

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> ein_geom<SPAN class="punctuation token">.</SPAN>__file__
<SPAN class="string token">'/private/var/mobile/Containers/Shared/AppGroup/A9DDA80F-9432-45DA-B931-2E9386579AE6/Pythonista3/Documents/Python_3_scripts/np/ein_geom.py'</SPAN>

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> <SPAN class="comment token"># even thought the script was run, __file__ doesn't exist, until it is imported.</SPAN>
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> making sys<SPAN class="punctuation token">.</SPAN>argv<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> the only sure way to know what script <SPAN class="keyword token">is</SPAN> being run<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

curtvprice

Dan, I am still dense here. There is no script file (ie module) here in this dialog below except the current process. Why would one expect __file__ or sys.argv[0] to be defined in this context at all?

python
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> <SPAN class="keyword token">import</SPAN> sys
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> sys<SPAN class="punctuation token">.</SPAN>argv<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="string token">''</SPAN>
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> __file__
Traceback <SPAN class="punctuation token">(</SPAN>most recent call last<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
 File <SPAN class="string token">"<stdin>"</SPAN><SPAN class="punctuation token">,</SPAN> line <SPAN class="number token">1</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="keyword token">in</SPAN> <SPAN class="operator token"><</SPAN>module<SPAN class="operator token">></SPAN>
NameError<SPAN class="punctuation token">:</SPAN> name <SPAN class="string token">'__file__'</SPAN> <SPAN class="keyword token">is</SPAN> <SPAN class="operator token">not</SPAN> defined
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN>‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

DanPatterson_Retired

start python on your system... do absolutely nothing... do a 'dir' do a locals().keys(), run a script with

import sys

script = sys.argv[0]

what is script? Does __file__ exist in dir or locals.keys? On my operating system(s), it doesn't unless I import a module (as in my example), then __file__ exists and it refers to the module, not the script

curtvprice

__file__ ... it won't exist if you are just running a script...
__file__ doesn't exist as a property for the script... it does for imported modules.

??? I must be very dense. Please enlighten me.

In ArcGIS (or anywhere else) the main startup script (.py, .pyt, tbx[validation code]) would be the context you would normally need the pathname to find the tool's associated files, and I seem to be able to use __file__ there just fine. The dialog below is OSX.

Marcie<SPAN class="punctuation token">:</SPAN><SPAN class="operator token">~</SPAN> curtis$ cat x<SPAN class="punctuation token">.</SPAN>py
<SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>__file__<SPAN class="punctuation token">)</SPAN>
Marcie<SPAN class="punctuation token">:</SPAN><SPAN class="operator token">~</SPAN> curtis$ python x<SPAN class="punctuation token">.</SPAN>py
x<SPAN class="punctuation token">.</SPAN>py
Marcie<SPAN class="punctuation token">:</SPAN><SPAN class="operator token">~</SPAN> curtis$ python `pwd`<SPAN class="operator token">/</SPAN>x<SPAN class="punctuation token">.</SPAN>py
<SPAN class="operator token">/</SPAN>Users<SPAN class="operator token">/</SPAN>curtis<SPAN class="operator token">/</SPAN>x<SPAN class="punctuation token">.</SPAN>py‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

DanPatterson_Retired

Curtis ...__file__ doesn't exist as a property for the script... it does for imported modules.

try it python in windows and OSwhater machines, they behave differently. sys.argv[0] gives you the running script from which you can parse the path. If you import a toolbox or a python module (aka another script), it will have a __file__ property... just not the script that you are running... try it on different operating systems, and my comments were directed to python not arcmap explicitly

curtvprice

__file__ ... it won't exist if you are just running a script.

I do not understand, sir.

DanPatterson_Retired

I would caution against just relying on just... __file__ ... it won't exist if you are just running a script.

__file__ can be exploited if you have imported a module however, so always check using dir() to confirm the existence of a __file__ property first.

For example

>>> import os
>>> import sys

>>> dir()
['__all__', '__builtins__', '__cached__', '__doc__', '__loader__', '__name__', 
'__package__', '__spec__', '_data', ...snip..., 'art', ... snip ..., 'os',
 ... snip ..., 'sys']

>>> # ... now 'art' is an imported module

>>> dir(art)
['__all__', '__builtins__', '__cached__', '__doc__', '__file__',... snip ...]

>>> # ... it has a __file__ property which

>>> f = os.path.dirname(art.__file__)
>>> f
'/private/var/mobile/Containers/Shared/AppGroup/...some weird location thing .../Pythonista3/Documents/site-packages-3'
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍
Things can c<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

hange with the operating system and the version of python you are using. Fortunately ArcMap and Pro have a restricted number of options.... python runs on anything

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