列表解析
squares = []
for i in range(1,11):
square = i**2
squares.append(square)
print squares
##########
sa = [value**2 for value in range(1,11)]
print sa
#这两段代码的结果一样
#列表复制
wa = ['jacl','tom','mary']
wb = wa[:]
print wa ##['jacl','tom','mary']
wc = wa[1:2]
print wc ##['tom','mary']