gmpy2 is not compulsory anymore.

Author: Guillaume Smith

README.rst

@@ -28,6 +28,16 @@ Or use nose::
 
    nosetests
 
+Note related to gmpy2
+---------------------
+
+`gmpy2` is not required to use the library, but is preferred. A pure Python implementation is available but 
+`gmpy2` drastically improves performances. As indication on a laptop not dedicated to benchmarking, running the example
+`examples/federated_learning_with_encryption.py` provided in the library took:
+ - 4.5s with `gmpy2` installed
+ - 35.7s without `gmpy2` installed
+
+However, `gmpy2` is a requirement to run the tests.
 
 Code History
 ------------

setup.py

@@ -56,9 +56,9 @@
     },
     extras_require={
         'cli': ['click'],
-        'examples': ['sklearn']
+        'examples': ['numpy', 'scipy', 'sklearn']
     },
-    install_requires=['gmpy2'],
-    tests_require=['numpy', 'click'],
+    install_requires=[],
+    tests_require=['click', 'gmpy2', 'numpy'],
     test_suite="phe.tests"
 )