离线环境下如何配置Cartopy全局共享的Natural Earth shapefiles路径？

Got it, let's fix this offline Cartopy shapefile problem once and for all. Since you're stuck in an offline environment and need a global shared location that every user can access (so Cartopy doesn't waste time trying to download files when it can't find them in the default ~/.local/share/cartopy/shapefiles/), here's exactly what you need to do:

First, choose a directory that all users on your system have read access to. Common, safe choices are:

• /usr/share/cartopy/shapefiles/
• /opt/cartopy_shapefiles/

1. Create the directory (run as root/sudo):

   sudo mkdir -p /usr/share/cartopy/shapefiles/
   

2. Copy your pre-downloaded Natural Earth shapefiles into this directory, making sure to keep the subdirectory structure Cartopy expects. For example:

   /usr/share/cartopy/shapefiles/
   ├── natural_earth_lowres/
   │   ├── ne_110m_admin_0_countries.shp
   │   ├── ne_110m_admin_0_countries.shx
   │   └── ne_110m_admin_0_countries.dbf
   └── natural_earth_10m/
       └── [your 10m resolution shapefile files]
   

3. Set proper permissions so all users can read the files:

   sudo chmod -R 755 /usr/share/cartopy/shapefiles/
   

You have two reliable methods—pick the one that fits your setup best:

Option 1: System-Wide Environment Variable (Recommended) #

This method doesn't require modifying code and persists across Python/Cartopy updates.

1. Edit a system-wide environment configuration file:
   • For Debian/Ubuntu-based systems, edit /etc/environment and add this line at the end:

     CARTOPY_DATA_DIR="/usr/share/cartopy/shapefiles/"
     

   • For RHEL/CentOS-based systems, create /etc/profile.d/cartopy.sh and add:

     export CARTOPY_DATA_DIR="/usr/share/cartopy/shapefiles/"
     

2. Make changes take effect: Either reboot the system, or have all users log out and log back in. Users can verify the variable is set by running:

   echo $CARTOPY_DATA_DIR
   

Option 2: Modify Cartopy's Default Config File #

Use this only if environment variables aren't feasible (note: this will be overwritten if you update Cartopy later):

1. Locate Cartopy's config.py file. It lives in your Python site-packages directory. For example:

   # For Python 3.10 on Ubuntu
   /usr/lib/python3.10/site-packages/cartopy/config.py
   

2. Open the file as root/sudo, find the data_dir line. It will look like:

   data_dir = os.path.expanduser(os.environ.get('CARTOPY_DATA_DIR',
                                               '~/.local/share/cartopy'))
   

3. Replace the default path ('~/.local/share/cartopy') with your global directory:

   data_dir = os.path.expanduser(os.environ.get('CARTOPY_DATA_DIR',
                                               '/usr/share/cartopy/shapefiles/'))
   

4. Save the file and exit.

Run a quick test script to confirm Cartopy uses the global files instead of trying to download:

import cartopy.crs as ccrs
import matplotlib.pyplot as plt

# Create a basic map with coastlines
ax = plt.axes(projection=ccrs.PlateCarree())
ax.coastlines(resolution='110m')  # This calls the lowres shapefiles
plt.savefig('test_map.png')
print("Test map created successfully—no download attempts!")

If this runs without errors and generates a map image, your setup is working correctly.

• Double-check subdirectory names in your global folder—Cartopy expects exact matches like natural_earth_lowres, natural_earth_10m, etc.
• If any user has a local ~/.local/share/cartopy/shapefiles/ folder with incomplete/corrupted files, delete it so Cartopy falls back to the global path.
• For the environment variable method, ensure the file you edit applies to all users (not just your personal shell config).

内容的提问来源于stack exchange，提问作者user3712093