import unittest
class KeyValueStore(object):
''' A key-value store example '''
def __init__(self):
self._store = {}
def put(self, key, value):
''' Puts a value in the store '''
self._store[key] = value
def get(self, key):
''' Gets a value from the store by its key '''
return self._store.get(key)
class TestKeyValueStore(unittest.TestCase):
''' A unit test for KeyValueStore '''
def test_put_key_already_exists(self):
''' Tests put when key already exists '''
# Set up
store = KeyValueStore()
store.put('same key twice', 'first time')
# Execute
store.put('same key twice', 'second time')
# Verify
self.assertEqual(store.get('same key twice'), 'second time')
self.assertEqual(len(store._store), 1)
# No shared state between tests => no cleanup required
if __name__ == '__main__':
unittest.main()
