Max sum non neighbours in list

max_sum_non_neighbours.py

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+''' This script solves the problem of calculating maximum sum 
+    of the non-neighbours in a list and provide the elements 
+    making this maximum sum along with the sum.
+    This script works for mixed (positive and negative) number list
+    
+    Script doesn't do of the input parameters
+    It takes input from the user
+'''
+
+
+def list_has_negative_numbers_only(num_list):
+    '''This function checks if the given input list 
+       num_list has only negative numbers
+       returns - True, if it has only negative numbers
+                 False, if not
+    '''
+    ele_count = 0
+    for item in num_list:
+        if item < 0:
+            ele_count += 1
+
+    if ele_count == len(num_list):
+        return True
+    else:
+        return False
+
+
+def get_max_sum_list(num_list):
+    '''This function takes num_list a number list as input 
+    processes the list to find the maximum sum of the 
+    non-neighbour numbers and the numbers that make this sum
+    Input  : num_list - a number list 
+    Output : (max_sum, max_sum_list) - a tuple with maximum sum
+             and the numbers list that make up this sum
+    '''
+    if not isinstance(num_list, list):
+        raise ValueError("Expecting list as input")
+
+    incl_list = []
+    excl_list = []
+    index = 0
+    for num in num_list:
+        if num > 0:
+            incl = num
+            incl_list.append(num)
+            break
+        index += 1
+
+    excl = 0
+    for num in num_list[index + 1:]:
+        if num > 0:
+            temp = incl
+            if incl < excl + num:
+                temp_list = incl_list.copy()
+                incl_list = excl_list.copy()
+                incl_list.append(num)
+                excl_list = temp_list.copy()
+                incl = excl + num
+            excl = temp
+            if incl == excl:
+                excl_list = incl_list.copy()
+        else:
+            temp = incl
+            incl = max(incl, excl + 0)
+            excl = incl
+            excl_list = incl_list.copy()
+    return max(incl, excl), incl_list
+
+
+def main():
+    number_of_elements = int(input("Enter number of elements in the list?"))
+    print("Enter list elements(only integer data allowed)")
+    index = 0
+    num_list = []
+    while index < number_of_elements:
+        try:
+            element = int(input())
+        except Exception as exp:
+            print("Invalid input, enter integer only")
+            continue
+        num_list.append(element)
+        index += 1
+    if not list_has_negative_numbers_only(num_list):
+        max_sum, sum_list = get_max_sum_list(num_list)
+        print("Maximum sum : ", max_sum)
+        print("Elements making maximum sum")
+        print(sum_list)
+    else:
+        print("Maximum sum : ", max(num_list))
+        print("Elements making maximum sum")
+        print("[" + str(max(num_list)) + "]")
+
+
+main()