习题12:Reverse|习题12:Reverse or rotate? 习题12:Reverseorrotate?

【习题12:Reverse|习题12:Reverse or rotate?】是倒置呢还是错位

The input is a string str of digits. Cut the string into chunks of size sz (ignore the last chunk if its size is less than sz).If a chunk represents an integer such as the sum of the cubes of its digits is divisible by 2, reverse it; otherwise rotate it to the left by one position. Put together these modified chunks and return the result as a string.

Examples: revrot("123456987654", 6) --> "234561876549" revrot("123456987653", 6) --> "234561356789" revrot("66443875", 4) --> "44668753" revrot("66443875", 8) --> "64438756" revrot("664438769", 8) --> "67834466" revrot("123456779", 8) --> "23456771" revrot("", 8) --> "" revrot("123456779", 0) --> ""

def revrot(strng, sz): # your code # slice to chunks e.g strng[(n-1)*sz: n*sz] if sz <= 0: return '' r = '' for k in range(len(strng)//sz): chunk = strng[k*sz:(k+1)*sz] if sum(int(i) for i in chunk)%2 == 0: chunk = chunk[::-1] else: chunk = chunk[1:]+chunk[0] r += chunk return r