Python is widely used in GIS for spatial data analysis and automation. Two popular libraries are ArcPy (Esri’s Python library for ArcGIS) and GeoPandas (an open-source library built on Pandas). ArcPy is a comprehensive, proprietary package that provides hundreds of geoprocessing tools for spatial analysis, data management, and map automation. In contrast, GeoPandas is an open-source project that extends Pandas to support geospatial data types (GeoSeries and GeoDataFrame). Both enable spatial operations in Python but target different environments and use cases.
ArcPy: Python in ArcGIS
ArcPy (part of the ArcGIS platform) is a Python site package installed with ArcGIS Pro/Desktop. It provides access to ArcGIS’s built-in geoprocessing tools (over 1,400 tools) for functions like buffering, spatial joins, raster analysis, network analysis, etc. ArcPy includes specialized modules – for example, arcpy.sa
for Spatial Analyst (raster analytics) and arcpy.mp
(or arcpy.mapping
in ArcMap) for map automation. Notably, the arcpy.mapping/arcpy.mp module can export map documents or layouts to PDF/images, enabling batch map production. Because ArcPy is tied to ArcGIS, using it requires ArcGIS Pro (or ArcGIS Engine/Server) to be installed and licensed. In practice, ArcPy is common in enterprise GIS workflows: scripts can automate repetitive tasks (e.g. reprojecting many feature classes to a common CRS), batch-create geodatabases, update attributes, and integrate with ArcGIS projects.
- Capabilities: Provides all core ArcGIS geoprocessing tools (e.g., buffer, intersect, raster calculator) and advanced analytics (e.g., spatial statistics, geostatistical and spatially-aware machine learning models).
- Mapping/Automation: The mapping module allows automating map layouts and exports. For example, ArcPy scripts can update symbols, replace data sources, and export multiple map pages to PDF.
- Environment: Runs only in ArcGIS’s Python environment (Windows). It cannot be used standalone; ArcGIS Pro must be installed. ArcPy itself is not open-source and requires the ArcGIS license.
- Typical Use: GIS professionals use ArcPy within ArcGIS for tasks like large-scale spatial data processing and automated map production. For instance, one ArcGIS tutorial uses ArcPy to batch-project Washington, D.C. road and bike-rack layers so they share a common spatial reference.
GeoPandas: Python GIS with Pandas
GeoPandas is an open-source Python library designed for geospatial data analysis. It introduces two main data structures: a GeoDataFrame
(subclass of pandas.DataFrame
) and a GeoSeries
(subclass of pandas.Series
) that store geometric objects (points, lines, polygons). Users can have multiple geometry columns, but one is “active” for spatial operations. GeoPandas relies on other open libraries: Shapely for geometry operations, pyproj for projections, Fiona/pyogrio for file I/O, and pandas for data handling. It also integrates with matplotlib for plotting. GeoPandas excels at reading/writing common vector formats (Shapefile, GeoJSON, GeoPackage, etc.) and performing spatial operations (e.g. buffering, overlay, spatial join) in a Python data science workflow. For example, GeoPandas is often used to merge geographic data with attribute tables and plot maps from Jupyter notebooks.
- Data structures: A
GeoDataFrame
can store one or more geometry columns; itsGeoDataFrame.geometry
attribute returns the active geometry (with CRS info). AGeoSeries
holds the shapes, and pandas operations (groupby, join, arithmetic) apply alongside shapely’s geometry methods. - Capabilities: Supports vector data analysis: spatial joins, grouping, dissolves, overlays, and geometric computations (area, distance, etc.). For example, GeoPandas can easily identify points within polygons or calculate polygon areas. It can be combined with rasterio or PySAL for advanced workflows.
- Dependencies: Pure-Python and open-source. Installable via
pip
orconda
(conda recommended due to binary GIS libs). Depends on packages like pandas, Shapely, pyproj, pyogrio/Fiona, rtree (for spatial indexing) - Typical Use: Popular in research, data science, and open-data projects. Users leverage GeoPandas for exploratory GIS (e.g. analyzing city zones, environmental study areas) and integrate it with Python’s data stack. Unlike ArcPy, GeoPandas runs on any OS and has no licensing fees.
Comparison of ArcPy and GeoPandas
The table below summarizes key differences:
Feature | ArcPy (ArcGIS) | GeoPandas |
---|---|---|
License/Source | Proprietary (part of Esri ArcGIS; requires ArcGIS license) | Open-source (BSD-licensed) |
Environment | Windows only (installed with ArcGIS Pro/Desktop)Python env comes from ArcGIS | Cross-platform Python package; install via pip/conda (needs GDAL/GEOS) |
Data Support | Comprehensive: handles vector (points/lines/polygons), raster, TINs, etc. via ArcGIS tools | Vector only (points/lines/polygons). Reads shapefile/GeoJSON/GeoPackage etc. |
Dependencies | Requires ArcGIS software (Pro/Engine/Server) and its Python kernel | Depends on Python libraries: pandas, shapely, pyproj, Fiona/pyogrio, etc. |
Capabilities | Full GIS suite: advanced geoprocessing (raster analysis, network, spatial stats); map automation (arcpy.mapping) | Spatial data manipulation in Pandas: spatial joins, overlays, vector geometry ops; basic plotting via matplotlib |
Typical Use Cases | Enterprise GIS: large-scale automation (e.g., batch re-projections, data management); cartographic automation; use in government or corporate GIS | Data analysis & research: exploratory GIS in notebooks; merging spatial and tabular data; story-mapping (e.g., visualizing real-estate or population trends); working with open data |
Community & Cost | Supported by Esri (documentation, paid training). Licensing costs apply. | Supported by open-source community (forums, Slack/Gitter, StackOverflow). Free to use. |
Notable Use Cases
- ArcPy: Used widely in traditional GIS projects. For example, ArcPy scripts can batch-process transportation or infrastructure layers: an Esri tutorial uses ArcPy to project multiple DC roads and bike-rack shapefiles so they share a common CRS. The mapping module can automate map book creation from an ArcMap document. In industry, ArcPy is applied to environmental analysis (watershed modeling, land-use change), utility network management, and any task needing ArcGIS’s full geoprocessing power.
- GeoPandas: Common in data-driven projects. It’s often combined with pandas workflows to analyze open data. For instance, a geoscience workshop used GeoPandas (with Rasterio) to compute total distance traveled by ships in Alaskan fishing zones. GeoPandas is also used in urban planning or public health studies to merge spatial and statistical data – for example, mapping neighborhood boundaries with socio-economic attributes. Its ease-of-use makes it a go-to tool for quick GIS analyses in Python.
Resources and Community
- ArcPy/ArcGIS: The ArcGIS Pro Python documentation (ArcPy reference) is the authoritative sourcepro.arcgis.com. Esri’s online resources include the ArcGIS Python blog and sample code repositories. The ArcGIS Developer site also covers related Python libraries. For community help, the Esri Community (Python section) and GIS StackExchange have many ArcPy questions. (ArcPy code itself is not on GitHub, but the ArcGIS REST/Python APIs are on Esri’s GitHub.)
- GeoPandas: The GeoPandas GitHub repository hosts the source code, issue tracker, and documentationgithub.com. The official docs (geopandas.org) provide a user guide and examplesgeopandas.org. Community support is vibrant: ask questions on StackOverflow or GIS StackExchange (using the “geopandas” tag)github.com. The GeoPandas project also has a Gitter chat room and mailing list for discussionsgithub.com. Finally, broader Python GIS forums (e.g. PyData, GIS mailing lists) are good resources.
Learning Resources
- ArcPy: Esri provides official documentation and tutorials. The ArcGIS Pro Help has an ArcPy reference and guides (e.g. “What is ArcPy?”pro.arcgis.com). The ArcGIS Learn site offers step-by-step lessons (e.g. “Get started with Python in ArcGIS Pro”learn.arcgis.com). Esri Press publishes books like Python Scripting for ArcGIS Prolearn.arcgis.com for in-depth study. Training platforms (Esri Academy, Udemy, Coursera) offer courses on ArcPy and the ArcGIS Python API. The Esri Community (forums) and GIS StackExchange are active places to ask ArcPy questionsesri.com.
- GeoPandas: The official GeoPandas website and docs include a tutorial and example gallerygeopandas.org. Free online tutorials include blog posts (e.g. “Starter tutorial on GeoPandas”medium.com) and video courses (e.g. GeoDelta Labs’ 2.5-hour GeoPandas overviewclasscentral.com). Platforms like DataCamp and YouTube have GeoPandas tutorials. Paid training (e.g. courses on Udemy or Coursera) often cover GeoPandas as part of GIS/data-science tracks.