Setting CRS with EPSG code when writting shapefile with Fiona

Question

How to set the CRS when writing an ESRI Shapefile using Fiona on a modern Python version (>3.x)?

Why "modern"? Because Python 2 is now deprecated and this user asked a similar question for Python 2.7, which received (now probably) old fashioned answers: Fiona fails to write CRS to shapefile

Answer 1

This should work out of the box with fiona.__version__ : '1.8.20' (Python 3.6.9):

import fiona
from shapely.geometry import Point, mapping

my_schema = {
    'geometry': 'Point',
    'properties': {
        'id': 'int',
        'attribute1': 'float'},
}

my_id = 1
a_shapely_point = Point(9.17044, 45.45340)

with fiona.open('/path/to/shapefile.shp',
                mode='w',
                driver='ESRI Shapefile', 
                crs='epsg:4326', # <-------- Set CRS here using EPSG code!
                schema=my_schema) as c:
    c.write(
        {
            'geometry': mapping(a_shapely_point),
            'properties': {'id': my_id, 'attribute1': 3.1415},
        }
    )

You can then check it has been correctly written with ogrinfo for example:

$ cd /path/to
$ ogrinfo -so -ro -al shapefile.shp 

INFO: Open of `shapefile.shp'
      using driver `ESRI Shapefile' successful.

Layer name: test
Metadata:
  DBF_DATE_LAST_UPDATE=2021-07-14
Geometry: Point
Feature Count: 1
Extent: (9.170440, 45.453400) - (9.170440, 45.453400)
Layer SRS WKT:
GEOGCRS["WGS 84",
    DATUM["World Geodetic System 1984",
        ELLIPSOID["WGS 84",6378137,298.257223563,
            LENGTHUNIT["metre",1]]],
    PRIMEM["Greenwich",0,
        ANGLEUNIT["degree",0.0174532925199433]],
    CS[ellipsoidal,2],
        AXIS["latitude",north,
            ORDER[1],
            ANGLEUNIT["degree",0.0174532925199433]],
        AXIS["longitude",east,
            ORDER[2],
            ANGLEUNIT["degree",0.0174532925199433]],
    ID["EPSG",4326]]
Data axis to CRS axis mapping: 2,1
id: Integer64 (18.0)
attribute1: Real (24.15)

It also loads flawlessly in QGIS.

Doc on fiona.open(): https://fiona.readthedocs.io/en/latest/fiona.html#fiona.open