【Python】while文～その3～　whileとelse

while文の中でelseを使用する例を以下に示します。

>>> count= 1
>>> while count<10:
...  print(count)
...  count+=1
... else:
...  print('else!!')
... 
1
2
3
4
5
6
7
8
9
else!!
>>>

>>> count= 1

>>> while count<10:

... print(count)

... count+=1

... else:

... print('else!!')

...

else!!

>>>

while文の後にelseの内容が実行されていることがわかります。

以下の例ではelseが2つ登場しますが、1つ目はif文のelseです。

2つ目のelseがwhile文のelseに該当します。

この例ではbreakでwhile文を抜けることになり、その場合else文が実行されません。

>>> count=0
>>> while count<10:
...  count+=1
...  if count==9:
...   break
...  else:
...   print('count is ',count)
... <span style="color: #ff0000;">else</span>:
...   print('No break')
...
count is  1
count is  2
count is  3
count is  4
count is  5
count is  6
count is  7
count is  8
>>>

>>> count=0

>>> while count<10:

... count+=1

... if count==9:

... break

... else:

... print('count is ',count)

... <span style="color: #ff0000;">else</span>:

... print('No break')

...

count is 1

count is 2

count is 3

count is 4

count is 5

count is 6

count is 7

count is 8

>>>

続いて、breakが実行されずにwhile文のelseが実行される例を示します。

>>> count=0 
>>> while count<10:
...  count+=1
...  if count==11:
...   break
...  else:
...   print('count is ',count) 
... else:
...   print('No break')
...
count is  1
count is  2
count is  3
count is  4
count is  5
count is  6
count is  7
count is  8
count is  9
count is  10
No break
>>>