Extract Rows with Common Difference Elements in Python

When it is required to extract rows with common difference elements, an iteration and a flag value is used.

Example

Below is a demonstration of the same

my_list = [[31, 27, 10], [8, 11, 12], [11, 12, 13], [6, 9, 10]]

print("The list is :")
print(my_list)

my_result = []

for row in my_list:
   temp = True
   for index in range(0, len(row) - 1):

      if row[index + 1] - row[index] != row[1] - row[0]:
         temp = False
         break

   if temp :
      my_result.append(row)

print("The resultant list is :")
print(my_result)

Output

The list is :
[[31, 27, 10], [8, 11, 12], [11, 12, 13], [6, 9, 10]]
The resultant list is :
[[11, 12, 13]]

Explanation

• A list of tuple is defined and is displayed on the console.

• An empty list is created.

• The list is iterated over, and a variable is assigned to ‘True’.

• The indices are also iterated over.

• If the difference between previous index and current index is not equal to the difference between the previous element and current element, the variable is assigned ‘False’.

• The control breaks out of it.

• In the end, if the variable’s value is ‘True’, the element is appended to the empty list.

• This is the output that is displayed on the console.