Allow to use the library without requests installed

pytaxonomies/api.py

@@ -2,11 +2,16 @@
 # -*- coding: utf-8 -*-
 
 import json
-import requests
 import os
 import collections
 import re
 
+try:
+    import requests
+    HAS_REQUESTS = True
+except ImportError:
+    HAS_REQUESTS = False
+
 
 class Entry():
 
@@ -132,6 +137,8 @@ class Taxonomies(collections.Mapping):
             return json.load(f)
 
     def __load_url(self, url):
+        if not HAS_REQUESTS:
+            raise Exception("Python module 'requests' isn't installed, unable to fetch the taxonomies.")
         return requests.get(url).json()
 
     def __make_uri(self, taxonomy_name):

tests/tests.py

@@ -3,6 +3,7 @@
 
 import unittest
 from pytaxonomies import Taxonomies
+import pytaxonomies.api
 
 
 class TestPyTaxonomies(unittest.TestCase):
@@ -44,6 +45,13 @@ class TestPyTaxonomies(unittest.TestCase):
     def test_amountEntries(self):
         list(self.taxonomies.values())[0].amount_entries()
 
+    def test_missingDependency(self):
+        pytaxonomies.api.HAS_REQUESTS = False
+        with self.assertRaises(Exception):
+            Taxonomies()
+        Taxonomies(manifest_path="./misp-taxonomies/MANIFEST.json")
+        pytaxonomies.api.HAS_REQUESTS = True
+
 
 if __name__ == "__main__":
     unittest.main()