解法一

def getMiddle(words):
    if len(words)>2 and len(words)%2==0:
        return words[int(len(words)/2)-1:int(len(words)/2)+1]
    elif len(words)>2 and len(words)%2!=0:
        return words[int(len(words)/2)]
    elif len(words)==2:
        return words
    else:
        return words
    
assert getMiddle('testing')=='t'
assert getMiddle('test')=='es'
assert getMiddle('middle')=='dd'
assert getMiddle('AA')=='AA'
assert getMiddle('t')=='t'

3%2 #1
4%2 #0
4/2 #2.0
3/2 #1.5