Циклический сдвиг влево

#from random import randrange as rnd
# 1
a = [1,2,3,4,5,6,7,8,9]
a = a[1:]+a[:1]
print(a)

# 2
a = [1,2,3,4,5,6,7,8,9]
a = a + [a.pop(0)]
print(a)


# 3

a = [1,2,3,4,5,6,7,8,9]
n = len(a)
t = a[0]
for i in range(n-1):
    a[i] = a[i+1]
a[-1] = t
print(a)


# 4
a = [1,2,3,4,5,6,7,8,9]
n = len(a)
for i in range(n-1):
    a[i],a[i+1] = a[i+1],a[i]
print(a)