If you’ve ever written any Python at all, the chances are you’ve used iterators without even realising it. Writing your own and using them in your programs can provide significant perfo… ...

Python has several ways you can add or remove items from a list: .append() inserts an item at the end of the list. For example, list_of_ints.append(4) would turn list_of_ints into the list [1,2,3,4] .

#2 create two lists to store all even and odd numbers from 1 to 20 individually even = [] # create a list for even numbers odd = [] # create a list for odd numbers for k in range(1, 21): if k%2 == 0: ...

If you want to add items to a list in a loop, then you do have to declare an empty list beforehand. Don’t understand me wrong, there are a lot of nice Ideas in Python, but the overall language ...