Add variance and standard deviation

main.py

@@ -1,17 +1,18 @@
 import ast
+import math
 
-# Press Shift+F10 to execute it or replace it with your code.
-# Press Double Shift to search everywhere for classes, files, tool windows, actions, and settings.
 VERSION = "0.0.0"
 sContinue = True
 
-
 state = []
 
 
 def show_help():
     print("vector [5,6,7...] - set the current dataset to the given vector")
-    print("stdd - get the standard deviation of the current dataset")
+    print("stdev - get the standard deviation of the current dataset")
+    print("pstdev - get the population standard deviation of the current dataset")
+    print("variance - get the variance of the current dataset")
+    print("pvariance - get the population variance of the current dataset")
     print("mean - get the mean of the current dataset")
     print("median - get the median of the current dataset")
     print("mode - get the mode of the current dataset")
@@ -50,6 +51,48 @@ def get_median():
     return median
 
 
+def get_mode():
+    """
+    :return: The most frequent element in the global variable 'state'.
+    """
+    global state
+    from collections import Counter
+    mode = Counter(state).most_common(1)[0][0]
+    return mode
+
+
+def get_variance():
+    global state
+    n = len(state)
+
+    mean = get_mean()
+
+    variance = sum((x - mean) ** 2 for x in state) / (n - 1)
+    return variance
+
+
+def get_population_variance():
+    global state
+    n = len(state)
+
+    mean = get_mean()
+
+    variance = sum((x - mean) ** 2 for x in state) / n
+    return variance
+
+
+def get_standard_deviation():
+    variance = get_variance()
+    std_dev = math.sqrt(variance)
+    return std_dev
+
+
+def get_population_standard_deviation():
+    pvariance = get_population_variance()
+    std_dev = math.sqrt(pvariance)
+    return std_dev
+
+
 def start_shell():
     global state
     state = []
@@ -75,6 +118,18 @@ def handle_input():
             print(f"Set state to: {value}")
         case 'mean':
             print(get_mean())
+        case 'median':
+            print(get_median())
+        case 'mode':
+            print(get_mode())
+        case 'stdev':
+            print(get_standard_deviation())
+        case 'pstdev':
+            print(get_population_standard_deviation())
+        case 'variance':
+            print(get_variance())
+        case 'pvariance':
+            print(get_population_variance())
         case 'print':
             if state is not None:
                 print(f"{state}")