how to increment the iterator from inside for loop in python 3?

Save a copy of the iterator as a named object. Then you can skip ahead if you want to.

>>> myiter = iter(range(0, 10))>>> for i in myiter:    print(i)    next(myiter, None)...02468

You can't do that inside a for loop. Because every time that the loop gets restarted it reassign the variable i (even after you change it inside the loop) and every time you just increase the reassigned variable. If you want to do such thing you better to use a while loop and increase the throwaway variable manually.

>>> i=0>>> while i< 10 :...     print(i)...     i +=2...     print("increased i", i)... 0('increased i', 2)2('increased i', 4)4('increased i', 6)6('increased i', 8)8('increased i', 10)

Beside that, if you want to increase the variable on a period rather than based some particular condition, you can use a proper slicers to slice the iterable in which you're looping over.

For instance if you have an iterator you can use itertools.islice() if you have a list you can simply use steps while indexing (my_list[start:end:step]).

range() has an optional third parameter to specify the step. Use that to increment the counter by two. For example:

for i in range(0, 10, 2):    print(i)    print("increased i", i)

The reason that you cannot increment i like a normal variable is because when the for-loop starts to execute, a list (or a range object in Python 3+) is created, and i merely represents each value in that object incrementally.