Python for else笔记

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Python for else笔记

(1)在for 循环中，如果没有从任何一个break中退出，则会执行和for对应的else;只要从break中退出了，则else部分不执行

Demo Code:

for i in (6,5,4,5,6,1,3,4,9):
if i >= 5:
print "yes i>=5 i : %d ------>Continue" % i
continue
else:
print "no i < 5 i : %d ----->Break" % i
break
else:
print "into else Branch: i = %d" % i
print "--------------Demo end--------------------------"

Out Put:

yes i>=5 i : 6 ------>Continue
yes i>=5 i : 5 ------>Continue
no i < 5 i : 4 ----->Break
--------------Demo end--------------------------

解析：由于进入了Break分支，else分支没有执行：

（2）如果没有break则，else输出最后一次遍历的值;如Demo Code没有进入break分支最后输出为最后一个元素9

Demo Code:

for i in (6,5,4,5,6,1,3,4,9):

if i <= 10:
print "yes i<=10 i : %d ------>Continue" % i
continue
else:
print "no i > 10 i : %d ----->Break" % i
break
else:
print "into else Branch: i = %d" % i
print "--------------Demo end--------------------------"

Out put:

yes i<=10 i : 6 ------>Continue
yes i<=10 i : 5 ------>Continue
yes i<=10 i : 4 ------>Continue
yes i<=10 i : 5 ------>Continue
yes i<=10 i : 6 ------>Continue
yes i<=10 i : 1 ------>Continue
yes i<=10 i : 3 ------>Continue
yes i<=10 i : 4 ------>Continue
yes i<=10 i : 9 ------>Continue
into else Branch: i = 9
--------------Demo end--------------------------

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