Finding out whether an EPSG code is geographic or projected in Python

Question

Can one tell that from the number of digits or a similar rule?

Answer 1

You can use PyCRS library.

import pycrs

crs3857 = pycrs.parse.from_epsg_code(3857)
print("EPSG:3857 is " + crs3857.cs_type)

crs4326 = pycrs.parse.from_epsg_code(4326)
print("EPSG:4326 is " + crs4326.cs_type)

Output:

EPSG:3857 is Projected
EPSG:4326 is Geographic

You can also use isinstance method of Python with PyCRS:

isinstance(crs3857, pycrs.ProjCS)
# True

isinstance(crs4326, pycrs.GeogCS)
# True

Answer 2

The best way, I guess, is to use pyproj itself.

from pyproj import CRS

crs3857 = CRS(3857) # Web Mercator
crs4326 = CRS(4326) # WGS84

crs3857.is_projected  # True
crs3857.is_geographic # False

crs4326.is_projected  # False
crs4326.is_geographic # True