for one and all
for variable in list_name:
more with “for”
animals = ["cat","ant","bat"]
animals.sort（）
for animal in animals:
print animal
练习
写一个for loop遍历start_list,and .append（）s each number squared （x2）to square_list
then sortsquare_list
start_list =[5,3,1,2,4]
square_list=[]
for number in start_list
square_list.append(number**2)
square_list.sort（）
print square_list
