Allow API key to be set by env var

Author: Samuel Scully

opencage/geocoder.py

@@ -131,9 +131,12 @@ class OpenCageGeocode:
 
     session = None
 
-    def __init__(self, key, protocol='https', domain=DEFAULT_DOMAIN, sslcontext=None, user_agent_comment=None):
+    def __init__(self, key=None, protocol='https', domain=DEFAULT_DOMAIN, sslcontext=None, user_agent_comment=None):
         """Constructor."""
-        self.key = key
+        self.key = key if key is not None else os.environ.get('OPENCAGE_API_KEY')
+
+        if self.key is None:
+            raise ValueError("API key not provided. Either pass a 'key' parameter or set the OPENCAGE_API_KEY environment variable.")
 
         if protocol and protocol not in ('http', 'https'):
             protocol = 'https'

test/test_geocoder_args.py

@@ -0,0 +1,26 @@
+# encoding: utf-8
+
+from opencage.geocoder import OpenCageGeocode
+
+import os
+
+
+def test_protocol_http():
+    """Test that HTTP protocol can be set correctly"""
+    geocoder = OpenCageGeocode('abcde', protocol='http')
+    assert geocoder.url == 'http://api.opencagedata.com/geocode/v1/json'
+
+
+def test_api_key_env_var():
+    """Test that API key can be set by an environment variable"""
+
+    os.environ['OPENCAGE_API_KEY'] = 'from-env-var'
+    geocoder = OpenCageGeocode()
+    assert geocoder.key == 'from-env-var'
+
+
+def test_custom_domain():
+    """Test that custom domain can be set"""
+    geocoder = OpenCageGeocode('abcde', domain='example.com')
+    assert geocoder.url == 'https://example.com/geocode/v1/json'
+