### while loops
定義與實例
~~~
i = 0
numbers = []
while i < 6:
print "At the top i is %d" % i
numbers.append(i)
i = i + 1
print "Numbers now: ", numbers
print "At the bottom i is %d" % i
print "The numbers: "
for num in numbers:
print num，
~~~
輸出
~~~
At the top i is 0
Numbers now: [0]
At the bottom i is 1
At the top i is 1
Numbers now: [0, 1]
At the bottom i is 2
At the top i is 2
Numbers now: [0, 1, 2]
At the bottom i is 3
At the top i is 3
Numbers now: [0, 1, 2, 3]
At the bottom i is 4
At the top i is 4
Numbers now: [0, 1, 2, 3, 4]
At the bottom i is 5
At the top i is 5
Numbers now: [0, 1, 2, 3, 4, 5]
At the bottom i is 6
The numbers:
0 1 2 3 4 5
~~~
### for loops
定義和實例
~~~
elements = []
# then use the range function to do 0 to 5 counts
for i in range(0, 6):
print "Adding %d to the list." % i
# append is a function that lists understand
elements.append(i)
~~~
### A&Q
**What's the difference between a?for-loop**and a?**while-loop**?
ans: ??A?for-loop?can only iterate (loop) "over" collections of things. A?while-loop?can do any kind of iteration (looping) you want. However,?while-loops?are harder to get right and you normally can get many things done with?for-loops.
