Here's the corrected code:
```
def selection_sort(my_list):
list_length = len(my_list)
for i in range(list_length - 1):
# Set lowest to the element of the list located at index i
lowest = my_list[i]
index = i
# Iterate again over the list starting on the next position of the i variable
for j in range(i+1, list_length):
# Compare whether the element of the list located at index j is smaller than lowest
if my_list[j] < lowest:
index = j
lowest = my_list[j]
my_list[i], my_list[index] = my_list[index], my_list[i]
return my_list
my_list = [6, 2, 9, 7, 4, 8]
selection_sort(my_list)
print(my_list)
```
The code defines a selection_sort function that sorts a list using the selection sort algorithm. It takes one parameter: my_list, which is the list to be sorted. It starts by getting the length of the list and looping through all elements except the last one. In each iteration of the loop, it sets lowest to the element of the list located at index i and index to i. Then, it loops through all elements starting from the next position of the i variable. If an element is smaller than lowest, it sets index to the current position and lowest to the current element. After the inner loop finishes, it swaps the element at index i with the element at index index. This process continues until all elements have been sorted. Finally, it returns the sorted list. The code creates a list my_list, calls the selection_sort function with it, and prints the sorted list.