How to run a nested loop in python inside list such that the outer loop starts from the next element of the list always and so on

Try this code !

For each iteration of outer loop, you need to iterate the inner loop from 1 increment to the range of list.

Code :

arr = [1,5,2,0,4,2,7]
for i in range(0,len(arr)):
    print("Iteration # : ", i+1)
    for j in range(i+1,len(arr)):
        print("Outer loop value : " , arr[i] , " Inner loop value : " , arr[j])

Output :

Iteration # :  1                                                                                                       
Outer loop value :  1  Inner loop value :  5                                                                           
Outer loop value :  1  Inner loop value :  2                                                                           
Outer loop value :  1  Inner loop value :  0                                                                           
Outer loop value :  1  Inner loop value :  4                                                                           
Outer loop value :  1  Inner loop value :  2                                                                           
Outer loop value :  1  Inner loop value :  7                                                                           
Iteration # :  2                                                                                                       
Outer loop value :  5  Inner loop value :  2                                                                           
Outer loop value :  5  Inner loop value :  0                                                                           
Outer loop value :  5  Inner loop value :  4                                                                           
Outer loop value :  5  Inner loop value :  2                                                                           
Outer loop value :  5  Inner loop value :  7                                                                           
Iteration # :  3                                                                                                       
Outer loop value :  2  Inner loop value :  0                                                                           
Outer loop value :  2  Inner loop value :  4                                                                           
Outer loop value :  2  Inner loop value :  2                                                                           
Outer loop value :  2  Inner loop value :  7                                                                           
Iteration # :  4                                                                                                       
Outer loop value :  0  Inner loop value :  4                                                                           
Outer loop value :  0  Inner loop value :  2                                                                           
Outer loop value :  0  Inner loop value :  7                                                                           
Iteration # :  5                                                                                                       
Outer loop value :  4  Inner loop value :  2                                                                           
Outer loop value :  4  Inner loop value :  7                                                                           
Iteration # :  6                                                                                                       
Outer loop value :  2  Inner loop value :  7                                                                           
Iteration # :  7

You should try to iterate with indexes directly instead of elements it would be easier to start from the nex position in your list :

your_list = [1,5,2,0,4,2,7]
for index in range(len(your_list)):
    element_outer_loop = your_list[index]
    for index2 in range(index+1, len(your_list)):
        element_inner_loop = your_list[index2]

In the code that you have done you get bad result because your list contains multiple time a same value (2 for example) and when you call the index(sub_list1) it will return the first corresponding elements so it will be good for the first 2 but for the next it will return the position of the first.

The enumerate() method adds counter to an iterable and returns it (the enumerate object).

yx = [1,5,2,0,4,2,7]

for index,sub_list1 in enumerate(yx):
    for sub_list2 in yx[index+1:]:
        print(sub_list2)