Reset python iterator when I get value -

if got 10, 50, 100, 120, 140, 160, 100, 50 code:

mock_len = len(db)  epsilon = 20  max_data = 0  in range(mock_len - 1):      if db[i+1][0]-db[i][0] == 20:          max_data = db[i+1]            print max_data

will print 120,140,160, want print 1 value, in case 120, how reset 0 max_data var when value in order contue compare in loop.

let's 120, 120 max_data initial var, reset max_data 0 , continue comparing. have bigger list of data want 1 value when encounter 20 diff.

as said in comments, querstion unclear. below longshot attempt.

db = [10, 50, 100, 120, 140, 160, 100, 50] g = [db[i] i, _ in enumerate(db) if db[i]-db[i-1] == 20] print(g)     # [120, 140, 160] :prints instances difference 20 print(g[0])  #            120  :prints first instance difference 20 

you not need reset first instance of something. alternatively, if want first 1 , don't want find them can use while loop. let write on own though.