Tutorial: Download data

Learn how to automate downloading data from portal using ArcGIS API for Python.

In this tutorial you will download and import data taken from the Los Angeles GeoHub using the ArcGIS API for Python. The data sets include a Trailheads (CSV), Trails (GeoJSON), and a Parks and Open Space (Shapefile) file.

The data will be stored locally on your machine.

Prerequisites

Steps

Import modules and log in

1. Import the GIS class and create a connection to ArcGIS Online. You will also load Path from pathlib and ZipFile from the Python standard library. Because the data is public, we can use an anonymous connection to ArcGIS Online to download the data.

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   from arcgis.gis import GIS
   from pathlib import Path
   from zipfile import ZipFile
   
   gis = GIS()
   
   

Access the item by ID

1. Create a variable to store the ID of the public data item.

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   from arcgis.gis import GIS
   from pathlib import Path
   from zipfile import ZipFile
   
   gis = GIS()
   
   public_data_item_id = 'a04933c045714492bda6886f355416f2'
   
   

2. The content property of a GIS object is an instance of a ContentManager class. This can be used to manage content in ArcGIS Online. The get() method makes an HTTP request to retrieve an Item object.

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   gis = GIS()
   
   public_data_item_id = 'a04933c045714492bda6886f355416f2'
   
   # `ContentManager.get` will return `None` if there is no Item with ID `a04933c045714492bda6886f355416f2`
   data_item = gis.content.get(public_data_item_id)
   data_item
   
   

Download the item

1. Download LA_Hub_datasets.zip to the notebook server's current location.

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   public_data_item_id = 'a04933c045714492bda6886f355416f2'
   
   # `ContentManager.get` will return `None` if there is no Item with ID `a04933c045714492bda6886f355416f2`
   data_item = gis.content.get(public_data_item_id)
   data_item
   
   # configure where to save the data, and where the ZIP file is located
   data_path = Path('./data')
   if not data_path.exists():
       data_path.mkdir()
   zip_path = data_path.joinpath('LA_Hub_Datasets.zip')
   extract_path = data_path.joinpath('LA_Hub_datasets')
   data_item.download(save_path=data_path)
   
   

2. Use ZipFile to extract the contents of the dataset.

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   # `ContentManager.get` will return `None` if there is no Item with ID `a04933c045714492bda6886f355416f2`
   data_item = gis.content.get(public_data_item_id)
   data_item
   
   # configure where to save the data, and where the ZIP file is located
   data_path = Path('./data')
   if not data_path.exists():
       data_path.mkdir()
   zip_path = data_path.joinpath('LA_Hub_Datasets.zip')
   extract_path = data_path.joinpath('LA_Hub_datasets')
   data_item.download(save_path=data_path)
   
   zip_file = ZipFile(zip_path)
   zip_file.extractall(path=data_path)
   
   

3. Call glob('*') on the extract_path to list the contents of the data directory.

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   from arcgis.gis import GIS
   from pathlib import Path
   from zipfile import ZipFile
   
   gis = GIS()
   
   public_data_item_id = 'a04933c045714492bda6886f355416f2'
   
   # `ContentManager.get` will return `None` if there is no Item with ID `a04933c045714492bda6886f355416f2`
   data_item = gis.content.get(public_data_item_id)
   data_item
   
   # configure where to save the data, and where the ZIP file is located
   data_path = Path('./data')
   if not data_path.exists():
       data_path.mkdir()
   zip_path = data_path.joinpath('LA_Hub_Datasets.zip')
   extract_path = data_path.joinpath('LA_Hub_datasets')
   data_item.download(save_path=data_path)
   
   zip_file = ZipFile(zip_path)
   zip_file.extractall(path=data_path)
   
   files = [file.name for file in extract_path.glob('*')]
   files