python3

辞書の中身を任意の変数に入れて繰り返し出力

2017年11月21日 by 河副太智 Leave a Comment

<span class="cm-variable">ruits</span> = {<span class="cm-string">"strawberry"</span>: <span class="cm-string">"red"</span>, <span class="cm-string">"peach"</span>: <span class="cm-string">"pink"</span>, <span class="cm-string">"banana"</span>: <span class="cm-string">"yellow"</span>}
<span class="cm-keyword">for</span> <span class="cm-variable">fruit</span>, <span class="cm-variable">color</span> <span class="cm-keyword">in</span> <span class="cm-variable">fruits</span>.<span class="cm-property">items</span>():
        <span class="cm-builtin">print</span>(<span class="cm-variable">fruit</span><span class="cm-operator">+</span><span class="cm-string">" is "</span><span class="cm-operator">+</span><span class="cm-variable">color</span>)

ruits = {"strawberry": "red", "peach": "pink", "banana": "yellow"}

for fruit, color in fruits.items():

print(fruit+" is "+color)

出力結果

<span class="cm-variable">strawberry</span> <span class="cm-keyword">is</span> <span class="cm-variable">red</span>
<span class="cm-variable">peach</span> <span class="cm-keyword">is</span> <span class="cm-variable">pink</span>
<span class="cm-variable">banana</span> <span class="cm-keyword">is</span> <span class="cm-variable">yellow</span>

strawberry is red

peach is pink

banana is yellow

リストの中身を任意の変数に入れて繰り返し出力

2017年11月21日 by 河副太智 Leave a Comment

fruits = [["strawberry", "red"],
["peach", "pink"],
["banana", "yellow"]]

for a,b in fruits:
print(a + " is " + b)

ifとcontinueの組み合わせ

2017年11月21日 by 河副太智 Leave a Comment

<span class="cm-variable">continueはスキップ（実行しない）

numbers</span> = [<span class="cm-number">1</span>, <span class="cm-number">2</span>, <span class="cm-number">3</span>]
<span class="cm-keyword">for</span> <span class="cm-variable">number</span> <span class="cm-keyword">in</span> <span class="cm-variable">numbers</span>:
    <span class="cm-keyword">if</span> <span class="cm-variable">number</span> == <span class="cm-number">2</span>:
        <span class="cm-keyword">continue</span>
    <span class="cm-builtin">print</span>(<span class="cm-variable">number</span>)

continueはスキップ（実行しない）

numbers = [1, 2, 3]

for number in numbers:

if number == 2:

continue

print(number)

を実行した時の出力結果は

<span class="cm-number">1</span>
<span class="cm-number">3</span>

1 2	<span class="cm-number">1</span> <span class="cm-number">3</span>

ifとbreakの組み合わせ

2017年11月21日 by 河副太智 Leave a Comment

<span class="cm-variable">numbers</span> = [<span class="cm-number">1</span>, <span class="cm-number">2</span>, <span class="cm-number">3</span>, <span class="cm-number">4</span>, <span class="cm-number">5</span>, <span class="cm-number">6</span>, <span class="cm-number">7</span>, <span class="cm-number">8</span>, <span class="cm-number">9</span>, <span class="cm-number">10</span>]
<span class="cm-keyword">for</span> <span class="cm-variable">number</span> <span class="cm-keyword">in</span> <span class="cm-variable">numbers</span>:
    <span class="cm-builtin">print</span>(<span class="cm-variable">number</span>)
    <span class="cm-keyword">if</span> <span class="cm-variable">number</span> <span class="cm-operator">&gt;</span>= <span class="cm-number">5</span>:
        <span class="cm-builtin">print</span>(<span class="cm-string">"続きはこちら"</span>)
        <span class="cm-keyword">break</span>

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

for number in numbers:

print(number)

if number >= 5:

print("続きはこちら")

break

この時の実行結果は、

<span class="cm-number">1</span>
<span class="cm-number">2</span>
<span class="cm-number">3</span>
<span class="cm-number">4</span>
<span class="cm-number">5</span>
<span class="cm-variable">続きはこちら</span>

1

2

3

4

5

続きはこちら

リストの要素を後の代入で変化させないようにする

2017年11月21日 by 河副太智 Leave a Comment

<span class="cm-variable">リストの要素は別の変数にリストごと移動させても</span>

1	<span class="cm-variable">リストの要素は別の変数にリストごと移動させても</span>

<span class="cm-variable">移動後のリストに変更があれば移動前の変数にあるリストも変化してしまう</span></code><code class="cm-s-ipython language-python"><span class="cm-variable">
</span></code><code class="cm-s-ipython language-python"></code><code class="cm-s-ipython language-python"><span class="cm-variable">
alphabet</span> = [<span class="cm-string">"a"</span>, <span class="cm-string">"b"</span>, <span class="cm-string">"c"</span>]
<span class="cm-variable">alphabet_copy</span> = <span class="cm-variable">alphabet</span>
<span class="cm-variable">alphabet_copy</span>[<span class="cm-number">0</span>] = <span class="cm-string">"A"</span>
<span class="cm-builtin">print</span>(<span class="cm-variable">alphabet</span>)  <span class="cm-comment"># ["A", "b", "c"]と出力される。</span>

移動後のリストに変更があれば移動前の変数にあるリストも変化してしまう</code><code class="cm-s-ipython language-python">

</code><code class="cm-s-ipython language-python"></code><code class="cm-s-ipython language-python">

alphabet = ["a", "b", "c"]

alphabet_copy = alphabet

alphabet_copy[0] = "A"

print(alphabet) # ["A", "b", "c"]と出力される。

それを防ぐためには、「y = x」とするのではなく「y = x[:]」or「y = list(x)」

リストの要素をforで取り出す

2017年11月20日 by 河副太智 Leave a Comment

<span class="cm-variable">animals</span> = [<span class="cm-string">"tiger"</span>, <span class="cm-string">"dog"</span>, <span class="cm-string">"elephant"</span>]
<span class="cm-keyword">for</span> n <span class="cm-keyword">in</span> <span class="cm-variable">animals</span>:
    <span class="cm-builtin">print</span>(n)

</code> in animalsで繰り返す回数を指定（リストの要素の数だけ繰り返す） 
for 直後の変数nにはリストの文字列が代入される

animals = ["tiger", "dog", "elephant"]

for n in animals:

print(n)

</code> in animalsで繰り返す回数を指定（リストの要素の数だけ繰り返す）

for 直後の変数nにはリストの文字列が代入される