OmkarPathak · OmkarPathak · Aug 16, 2017 · Aug 15, 2017
diff --git a/docs/Fibonacci.rst b/docs/Fibonacci.rst
@@ -18,8 +18,10 @@ Features
 --------
 
 * Fibonacci implementations available:
+    - Generator
+    - Golden ratio
+    - Memorization (which saves some recursions to avoid computation of same series again and again)
     - Recursion
-    - Cache (which saves some recursions to avoid computation of same series again and again)
 
 * Get the code used for any of the implementation
 
@@ -36,7 +38,7 @@ Features
 
     >>> from pygorithm.fibonacci import modules
     >>> modules()
-    ['cache', 'recursion']
+    ['generator', 'goldenratio', 'memoization', 'recursion']
 
 Implementations API
 -------------------

diff --git a/pygorithm/fibonacci/__init__.py b/pygorithm/fibonacci/__init__.py
@@ -1,3 +1,5 @@
-from pygorithm.fibonacci import cache
+from pygorithm.fibonacci import generator
+from pygorithm.fibonacci import goldenratio
+from pygorithm.fibonacci import memoization
+from pygorithm.fibonacci.modules import modules
 from pygorithm.fibonacci import recursion
-from . modules import modules
diff --git a/pygorithm/fibonacci/generator.py b/pygorithm/fibonacci/generator.py
@@ -0,0 +1,40 @@
+"""
+Fibonacci implementation through generator.
+"""
+
+import inspect
+
+
+def get_sequence(n):
+    """
+    Return Fibonacci sequence from zero to specified number as list.
+    """
+    def fib():
+        """
+        Return Fibonacci value by specified number as integer.
+
+        Golden ratio — https://en.wikipedia.org/wiki/Golden_ratio
+        Fibonacci's relation to the golden ratio — https://en.wikipedia.org/wiki/Fibonacci_number#Closed-form_expression
+        """
+        a, b = 0, 1
+
+        while True:
+            yield a
+
+            a, b = b, a + b
+
+    def sequence(n):
+        """
+        Return sequence of Fibonacci values as list.
+        """
+        f = fib()
+        return [f.__next__() for _ in range(n + 1)]
+
+    return sequence(n)
+
+
+def get_code():
+    """
+    Return source code of Fibonacci sequence logic's implementation.
+    """
+    return inspect.getsource(get_sequence)
diff --git a/pygorithm/fibonacci/goldenratio.py b/pygorithm/fibonacci/goldenratio.py
@@ -0,0 +1,39 @@
+"""
+Fibonacci implementation through golden ratio (math formula).
+"""
+
+import inspect
+import math
+
+
+def get_sequence(n):
+    """
+    Return Fibonacci sequence from zero to specified number as list.
+    """
+    def fib(n):
+        """
+        Return Fibonacci value by specified number as integer.
+
+        Golden ratio — https://en.wikipedia.org/wiki/Golden_ratio
+        Fibonacci's relation to the golden ratio — https://en.wikipedia.org/wiki/Fibonacci_number#Closed-form_expression
+        """
+        golden_ratio = (1 + math.sqrt(5)) / 2
+
+        val = (golden_ratio ** n - (1 - golden_ratio) ** n) / math.sqrt(5)
+
+        return int(val)
+
+    def sequence(n):
+        """
+        Return sequence of Fibonacci values as list.
+        """
+        return [fib(value) for value in range(n + 1)]
+
+    return sequence(n)
+
+
+def get_code():
+    """
+    Return source code of Fibonacci sequence logic's implementation.
+    """
+    return inspect.getsource(get_sequence)
diff --git a/pygorithm/fibonacci/cache.py → pygorithm/fibonacci/memoization.py b/pygorithm/fibonacci/cache.py → pygorithm/fibonacci/memoization.py
@@ -24,12 +24,13 @@ def fib(n):
 
     def sequence(n):
         """
-        Return sequence if Fibonacci values as list.
+        Return sequence of Fibonacci values as list.
         """
         return [fib(value) for value in range(n + 1)]
 
     return sequence(n)
 
+
 def get_code():
     """
     Return source code of Fibonacci sequence logic's implementation.

diff --git a/pygorithm/fibonacci/modules.py b/pygorithm/fibonacci/modules.py
@@ -1,13 +1,20 @@
+"""
+Find all modules in Fibonacci logic.
+"""
+
 import pkgutil
+
+import pygorithm.fibonacci
+
+
 def modules():
     """
-    Find all functions in pygorithm.data_structures
+    Find all functions in `pygorithm.fibonacci`.
     """
-    import pygorithm.fibonacci
     package = pygorithm.fibonacci
-    modules = []
-    for importer, modname, ispkg in pkgutil.iter_modules(package.__path__):
-        modules.append(modname)
-    modules.remove('modules')
-    modules.sort()
+
+    modules = sorted([
+        modname for _, modname, __ in pkgutil.iter_modules(package.__path__) if modname != 'modules'
+    ])
+
     return modules
diff --git a/pygorithm/fibonacci/recursion.py b/pygorithm/fibonacci/recursion.py
@@ -13,17 +13,14 @@ def fib(n):
         """
         Return Fibonacci value by specified number as integer.
         """
-        if n == 0:
-            return 0
-
-        if n == 1:
-            return 1
+        if n <= 1:
+            return n
 
         return fib(n - 1) + fib(n - 2)
 
     def sequence(n):
         """
-        Return sequence if Fibonacci values as list.
+        Return sequence of Fibonacci values as list.
         """
         return [fib(value) for value in range(n + 1)]
 

diff --git a/tests/test_fibonacci.py b/tests/test_fibonacci.py
@@ -4,7 +4,7 @@
 
 import unittest
 
-from pygorithm.fibonacci import cache, recursion
+from pygorithm.fibonacci import generator, goldenratio, memoization, recursion
 
 
 class TestFibonacciImplementations(unittest.TestCase):
@@ -16,7 +16,7 @@ def test_implementations_same_result(self):
         """
         Verify that all implementations have same result.
         """
-        fibonacci_implementations = [cache, recursion]
+        fibonacci_implementations = [generator, goldenratio, memoization, recursion]
 
         for implementation in fibonacci_implementations:
             result = getattr(implementation, 'get_sequence')(0)