update-GM.PY

maths/series/geometric_mean.py

@@ -1,3 +1,8 @@
+"""
+GEOMETRIC MEAN :  https://en.wikipedia.org/wiki/Geometric_mean
+"""
+
+
 def is_geometric_series(series: list) -> bool:
     """
     checking whether the input series is geometric series or not
@@ -8,14 +13,19 @@ def is_geometric_series(series: list) -> bool:
     True
     >>> is_geometric_series([1, 2, 3])
     False
+    >>> is_geometric_series([0, 0, 3])
+    False
 
     """
     if len(series) == 1:
         return True
-    common_ratio = series[1] / series[0]
-    for index in range(len(series) - 1):
-        if series[index + 1] / series[index] != common_ratio:
-            return False
+    try:
+        common_ratio = series[1] / series[0]
+        for index in range(len(series) - 1):
+            if series[index + 1] / series[index] != common_ratio:
+                return False
+    except ZeroDivisionError:
+        return False
     return True
 
 
@@ -29,23 +39,33 @@ def geometric_mean(series: list) -> float:
     8.48528137423857
     >>> geometric_mean([4, 8, 16])
     7.999999999999999
+    >>> geometric_mean(4)
+    Traceback (most recent call last):
+        ...
+    ValueError: Input series is not valid, valid series - [2, 4, 8]
     >>> geometric_mean([1, 2, 3])
     Traceback (most recent call last):
         ...
     ValueError: Input list is not a geometric series
+    >>> geometric_mean([0, 2, 3])
+    Traceback (most recent call last):
+        ...
+    ValueError: Input list is not a geometric series
     >>> geometric_mean([])
     Traceback (most recent call last):
         ...
     ValueError: Input list must be a non empty list
 
     """
+    if not isinstance(series, list):
+        raise ValueError("Input series is not valid, valid series - [2, 4, 8]")
     if len(series) == 0:
         raise ValueError("Input list must be a non empty list")
     if not is_geometric_series(series):
         raise ValueError("Input list is not a geometric series")
     answer = 1
-    for _ in series:
-        answer *= _
+    for value in series:
+        answer *= value
     return pow(answer, 1 / len(series))