Question

Write a function cycle(input_list) that performs an "in-place" cycling of the elements of a list, moving each element one position earlier in the list. Here "in place" means the operation should be performed by mutating the original list, and your function should not return anything. Note that you may assume that input_list is non-empty (i.e. contains at least one element)

For example:

>>> l = [1, 2, 4, 5, 'd']

>>> cycle(l)

>>> l

[2, 4, 5, 'd', 1]

>>> cycle(l)

>>> l

[4, 5, 'd', 1, 2]

Answer 1

def cycle(l):
    if len(l)==0:
        return
    a = l[0]
    l = l[1:]
    l.append(a)
    return l

lis = [1, 2, 4, 5, 'd']
print(lis)
lis = cycle(lis)
print(lis)

========================
See Output

New Project-20170903 t3 + ExecuteI >Share Code main.py x 1- def cycle(l): root main.py if len(1)-0: return 4 5 6 7 1 101: 1.append(a) return 9 lis [1, 2, 4, 5, 'd'] 10 print(lis) 11 lis -cycle(lis) 12 print(lis) 13 14 Default Term Browser sh-4.4$ python3 main.py sh-4.4$

Thanks, let me know if there is any concern.

def cycle(l):
    if len(l)==0:
        return
    a = l[0]
    del l[0]
    l.append(a)

lis = [1, 2, 4, 5, 'd']
cycle(lis)
print(lis)

lis = [2, 4, 5, 'd', 1]
cycle(lis)
print(lis)


====================================================================================

New Project-20170903 t+QExecute >Share Code main.py x if len(L)-0: a-10 L.append(a) root 1- def cycle(l): main.py return 4 7 9 10 cycle(lis) print(lis) 12 lis [2, 4, 5, 'd', 1] 13 cycle(lis) 14 print(lis) Default Term + Browser sh-4.4Ş python3 main.py sh-4.4$