Incrementing a for loop, inside the loop

You could use a while loop and increment i based on the condition:

while i < (len(foo_list)): 
    if foo_list[i] < bar: # if condition is True increment by 4
        i += 4
    else: 
        i += 1 # else just increment 1 by one and check next `foo_list[i]`

Using a for loop i will always return to the next value in the range:

foo_list = [1,2,3,4,5,6]
bar = 6
for i in range(len(foo_list)):
    print("range i ",i)
    if foo_list[i] < bar:
        i += 4
        print("if i",i)


('range i ', 0)
('if i', 4)
('range i ', 1)
('if i', 5)
('range i ', 2)
('if i', 6)
('range i ', 3)
('if i', 7)
('range i ', 4)
('if i', 8)
('range i ', 5)