Using Esri + python: arcpy notes

I shared a series of posts this week using Esri + arcpy tools on my Crime De-Coder LinkedIn page. LinkedIn eventually removes the posts though, so I am putting those same tips here on the blog. Esri’s tools do not have great coverage online, so blogging is a way to get more coverage in those LLM tools long term.


A little arcpy tip, if you import a toolbox, it can be somewhat confusing what the names of the methods are available. So for example, if importing some of the tools Chris Delaney has created for law enforcement data management, you can get the original methods available for arcpy, and then see the additional methods after importing the toolbox:

import arcpy
d1 = dir(arcpy) # original methods
arcpy.AddToolbox("C:\LawEnforcementDataManagement.atbx")
d2 = dir(arcpy) # updated methods available after AddToolbox
set(d2) - set(d1) # These are the new methods
# This prints out for me
# {'ConvertTimeField_Defaultatbx', 'toolbox_code', 'TransformCallData_Defaultatbx', 'Defaultatbx', 'TransformCrimeData_Defaultatbx'}
# To call the tool then
arcpy.TransformCrimeData_Defaultatbx(...)

Many of the Arc tools have the ability to copy python code, when I use Chris’s tool it copy-pastes arcpy.Defaultatbx.TransformCrimeData, but if running from a standalone script outside of an Esri session (using the python environment that ArcPro installs) that isn’t quite the right code to call the function.

You can check out Chris’s webinar that goes over the law enforcement data management tool, and how it fits into the different crime analysis solutions that Chris and company at Esri have built.


I like using conda for python environments on Window’s machines, as it is easier to install some particular packages. So I mostly use:

conda create --name new_env python=3.11 pip
conda activate new_env
pip install -r requirements.txt

But for some libraries, like geopandas, I will have conda figure out the install. E.g.

conda create --name geo_env python=3.11 pip geopandas
conda activate geo_env
pip install -r requirements.txt

As they are particularly difficult to install with many restrictions.

And if you are using ESRI tools, and you want to install a library, conda is already installed and you can clone that environment.

conda create --clone "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3" --name proclone
conda activate proclone
pip install -r requirements.txt

As you do not want to modify the original ESRI environment.


Using conda to run scheduled jobs in Windows is alittle tricky. Here is an example of setting up a .bat file (which can be set up in Windows scheduler) to activate conda, set a new conda environment, and call a python script.

::: For log, showing date/time
echo:
echo --------------------------
echo %date% %time%
::: This sets the location of the script, as conda may change it
set "base=%cd%"
::: setting up conda in Windows, example Arc's conda activate
call "C:\Program Files\ArcGIS\Pro\bin\Python\Scripts\activate.bat"
::: activating a new environment
call conda activate proclone
::: running a python script
call cd %base%
call python auto_script.py
echo --------------------------
echo:

Then, when I set up the script in Window’s scheduler, I often have the log file at that level. So the task scheduler I will have the action as:

"script.bat" >> log.txt 2>&1

And have the options where the script runs from the location of script.bat. This will append both the normal log and error log to the shell script. So if something goes wrong, you can open log.txt and see what is up.


When working with arcpy, often you need to have tables inside of a geodatabase to use particular geoprocessing tools. Here is an example of taking an external csv file, and importing that file into a geodatabase as a table.

import arcpy
gdb = "./project/LEO_Tables.gdb"
tt = "TempTable"
arcpy.env.workspace = gdb

# Convert CSV into geodatabase
arcpy.TableToTable_conversion("YourData.csv",gdb,tt)
#arcpy.ListTables() # should show that new table

# convert time fields into text, useful for law enforcement management tools
time_fields = ['rep_date','begin','end']
for t in time_fields:
    new_field = f"{t}2"
    arcpy.management.AddField(tt,new_field,"TEXT")
    arcpy.management.CalculateField(tt,new_field,f"!{t}!.strftime('%Y/%m/%d %H:%m')", "PYTHON3")

# This will show the new fields
#fn = [f.name for f in arcpy.ListFields(tt)]

When you create a new project, it automatically creates a geodatabase file to go along with that project. If you just want a standalone geodatabase though, you can use something like this in your python script:

import arcpy
import os

gdb = "./project/LEO_Tables.gdb"

if os.path.exists(gdb):
    pass
else:
    loc, db = os.path.split(gdb)
    arcpy.management.CreateFileGDB(loc,db)

So if the geodatabase does not exist, it creates it. If it does exist though, it will not worry about creating a new one.


One of the examples for automation is taking a basemap, updating some of the elements, and then exporting that map to an image or PDF. This sample code, using Dallas data, shows how to set up a project to do this. And here is the original map:

Because ArgGIS has so many different elements, the arcpy module tends to be quite difficult to navigate. Basically I try to seperate out data processing (which often takes inputs and outputs them into a geodatabase) vs visual things on a map. So to do this project, you have step 1 import data into a geodatabase, and 2 update the map elements. Here legend, title, copying symbology, etc.

You can go to the github project to download all of the data (including the aprx project file, as well as the geodatabase file). But here is the code to review.

import arcpy
import pandas as pd
from arcgis.features import GeoAccessor, GeoSeriesAccessor
import os

# Set environment to a particular project
gdb = "DallasDB.gdb"
ct = "TempCrimes"
ol = "ExampleCrimes"
nc = "New Crimes"
arcpy.env.workspace = gdb
aprx = arcpy.mp.ArcGISProject("DallasExample.aprx")
dallas_map = aprx.listMaps('DallasMap')[0]
temp_layer = f"{gdb}/{ct}"

# Load in data, set as a spatial dataframe
df = pd.read_csv('DallasSample.csv') # for a real project, will prob query your RMS
df = df[['incidentnum','lon','lat']]
sdf = pd.DataFrame.spatial.from_xy(df,'lon','lat', sr=4326)

# Add the feature class to the map, note this does not like missing data
sdf.spatial.to_featureclass(location=temp_layer)
dallas_map.addDataFromPath(os.path.abspath(temp_layer)) # it wants the abs path for this

# Get the layers, copy symbology from old to new
new_layer = dallas_map.listLayers(ct)[0]
old_layer = dallas_map.listLayers(ol)[0]
old_layer.visible = False
new_layer.symbology = old_layer.symbology
new_layer.name = nc

# Add into the legend, moving to top
layout = aprx.listLayouts("DallasLayout")[0]
leg = layout.listElements("LEGEND_ELEMENT")[0]
item_di = {f.name:f for f in leg.items}
leg.moveItem(item_di['Dallas PD Divisions'], item_di[nc], move_position='BEFORE')

# Update title in layout "TitleText"
txt = layout.listElements("TEXT_ELEMENT")
txt_di = {f.name:f for f in txt}
txt_di['TitleText'].text = "New Title"
# If you need to make larger, can do
#txt_di['TitleText'].elementWidth = 2.0

# Export to high res PNG file
layout.exportToPNG("DallasUpdate.png",resolution=500)

# Cleaning up, to delete the file in geodatabase, need to remove from map
dallas_map.removeLayer(new_layer)
arcpy.management.Delete(ct)

And here is the updated map:

Setting conda environments in crontab

I prefer using conda environments to manage python (partly out of familiarity). Conda is a bit different though, in that it is often set up locally for a users environment, and not globally as an installed package. This makes using it in bash scripts (or on windows .bat files) somewhat tricky.

So first, in a Unix environment, you can choose where to install conda. Then it adds into your .bashrc profile a line that looks something like:

__conda_setup="$('/mnt/miniconda/bin/conda' 'shell.bash' 'hook' 2> /dev/null)"
if [ $? -eq 0 ]; then
    eval "$__conda_setup"
else
    if [ -f "/lib/miniconda/etc/profile.d/conda.sh" ]; then
        . "/lib/miniconda/etc/profile.d/conda.sh"
    else
        export PATH="/lib/miniconda/bin:$PATH"
    fi
fi
unset __conda_setup

Where here I installed it in /lib. This looks complicated at first glance, but really all it is doing is sourcing the conda.sh script and pre-pending miniconda/bin to the path.

Now to be able to run python code on a regular basis in crontab, I typically have crontab run shell scripts, not python directly, so say that is a file run_code.sh:

#!/bin/sh

# Example shell script
time_start=`date +%Y_%m_%d_%H:%M`
echo "Begin script $time_start"

# Sourcing conda
source /lib/miniconda/etc/profile.d/conda.sh

# activating your particular environment
# may need to give full path, not just the name
conda activate your_env

# if you want to check environment
python --version

# you may need to change the directory at this point
echo "Current Directory is set to $PWD"
cd ...

# run your python script
log_file="main_log_$time_start.txt"
python main.py > $log_file 2>&1

I do not need to additionally add to the path in my experience, just sourcing that script is sufficient. Now edit your crontab (via crontab -e and using the VI editor) to look something like:

20 3 * * * bash /.../run_code.sh >> /.../cron_log.txt 2>&1

Where /.../ is shorthand for an explicit path to where the shell script and cron log lives.

This will run the shell script at 3:20 AM and append all of the stuff. In crontab if you just want conda available for all jobs, I believe you could do something like:

# global environment, can set keys, run scripts
some_key=abc
export some_key
source /lib/miniconda/etc/profile.d/conda.sh

20 3 * * * bash /.../run_code.sh >> /.../cron_log.txt 2>&1

But I have not tested this. If this works, you could technically run python scripts directly, but if you need to change environments you would still really need a shell script. It is good to know to be able to inject environment variables though in the crontab environment.

About the only other gotcha is file permissions. Sometimes in business applications you have service accounts running things, so a crontab as the service account. And you just need to make sure to chmod files so the service account has appropriate permissions. I tend to have more issues with log files by accident than I do conda environments though.

Note for people setting up scheduled jobs on windows, I have an example of setting a conda environment in a windows bat file.

Additional random pro-tip with conda environments while I am here – if you by default don’t want conda to set up new environments in your home directory (due to space or production processes), as well as download packages into a different cache location, you can do something like:

conda config --add pkgs_dirs /lib/py_packages
conda config --add envs_dirs /lib/conda_env

Have had issues in the past of having too much junk in home.

Crime De-Coder LLC Website

So I have created CRIME De-Coder LLC, a firm to do my consulting work with police departments. Check out my website, crimede-coder.com.

Feedback is welcome. In particular check out the services pages, and my first blog post on what distinguishes my services from most firms. Providing computer code to generate the end product is “teaching a man a fish”, whereas most firms just drop a final report and leave.

And of course feel free to reach out to consult@crimede-coder.com if you are interested in pursuing a project. Going forward I plan on making a new post around once a month, so sign up in your feed reader or using a service like IFTTT.


Setting up a stand alone website is not that hard in the end. Currently it is a static site with some custom javascript (hosted on Hostinger). I should do a PHP server for the new blog posts and RSS feed eventually, but for now this is fine. I suggest for those interested in the same get the Jon Duckett books (HTML/Javascript/PHP) for overview of the tech, and then check out Dani Kross’s youtube tutorials (for random things like editing the htaccess file).

I am not doing a newsletter for the blog-posts, as I am concerned it will get my email on random block lists. But if there is demand for it in the future I will figure out some other service I guess to do that.

I wanted a more bare-metal setup (not a hosted wordpress like this site), as in the future I will likely do demo’s of dashboards, host some pyscript, make a sign in for paid content, etc. I just wanted flexibility from the start. So stay tuned for more content from CRIME De-Coder!