# Python | Custom Cycle list

While working with Python lists, we can have a problem in which we need to perform the cycle of lists. This problem looks quite straight forward and has been discussed earlier. But sometimes, we need to perform it’s variations, hence making task challenging. We can have customizations such as elements from which cycling starts and Number of elements in cycle list. Let’s discuss solution to these variation.

Method : Using `dropwhile() + cycle() + islice()`
This task can be performed using combination of above functions. In this, the elements are dropped till K with `dropwhile()`, then the cycle can be done using `cycle()` and `islice()` is used to restrict the count of elements in list.

 `# Python3 code to demonstrate working of ` `# Custom Cycle list ` `# using dropwhile() + cycle() + islice() ` `import` `itertools ` ` `  `# initialize list ` `test_list ``=` `[``3``, ``4``, ``5``, ``7``, ``1``] ` ` `  `# printing original list ` `print``(``"The original list is : "` `+` `str``(test_list)) ` ` `  `# initialize element for start cycle ` `K ``=` `7` ` `  `# initialize size of cycle list  ` `N ``=` `12` ` `  `# Custom Cycle list ` `# using dropwhile() + cycle() + islice() ` `res ``=` `list``(itertools.islice(itertools.dropwhile(``lambda` `i: i !``=` `K, itertools.cycle(test_list)),  N)) ` ` `  `# printing result ` `print``(``"The cycled list is : "` `+` `str``(res)) `

Output :

```The original list is : [3, 4, 5, 7, 1]
The cycled list is : [7, 1, 3, 4, 5, 7, 1, 3, 4, 5, 7, 1]
```

My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :

Be the First to upvote.

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.