[Python] Loop 配合 else 的妙用
Python 算是用了滿久了，居然現在才發現這個神奇的用法。
Loop statements may have an else clause; it is executed when the loop terminates through exhaustion of the list (with for) or when the condition becomes false (with while), but not when the loop is terminated by a break statement.
也就是說 Python 中 for 以及 while 可以像 if 一樣有個 else 區塊，當迴圈沒有中斷就會執行到 else 區塊。
換句話說，就是 esle 為 for loop 的其中一個部份，如果 break 就一併跳出，沒有的話就會執行到。
nums = [60, 70, 30, 110, 90]
found = False
for n in nums:
if n > 100:
found = True
print "There is a number bigger than 100"
break
if not found:
print "Not found!"
nums = [60, 70, 30, 110, 90]
for n in nums:
if n > 100:
print "There is a number bigger than 100"
break
else:
print "Not found!"
如此一來，透過使用 else 可以節省一些 flag 的使用。