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HTML ファイル生成日時: 2024/11/24 14:07:03.493 (台灣標準時)

Python の dictionary の使い方

dictionary の簡単な使い方


#!/usr/pkg/bin/python3.9

# initialisation of a dictionary
fruit_price = {
    'apple': 50,
    'banana': 10,
    'cherry': 100,
}

# printing a whole dictionary
print (fruit_price)

# printing an element of a dictionary
print ('price of banana =', fruit_price['banana'])

実行してみると以下のようになる。
% ./test_dictionary_0.py 
{'apple': 50, 'banana': 10, 'cherry': 100}
price of banana = 10

辞書へのデータの追加方法

辞書へのデータの追加方法は以下の通り。

#!/usr/pkg/bin/python3.9

# initialisation of a dictionary
fruit_price = {}

# printing a whole dictionary
print (fruit_price)

# adding an element to a dictionary
fruit_price['apple'] = 50

# printing a whole dictionary
print (fruit_price)

# adding one more element to a dictionary
fruit_price['banana'] = 10

# printing a whole dictionary
print (fruit_price)

# adding one more element to a dictionary
fruit_price['cherry'] = 100

# printing a whole dictionary
print (fruit_price)

実行すると、次のようになる。
% ./test_dictionary_1.py
{}
{'apple': 50}
{'apple': 50, 'banana': 10}
{'apple': 50, 'banana': 10, 'cherry': 100}

ループを使って辞書のデータを取り出す

ループを使って辞書のデータを取り出す方法は以下の通り。

#!/usr/pkg/bin/python3.9

# initialisation of a dictionary
fruit_price = {
    'durian': 200,
    'cherry': 100,
    'apple':   50,
    'grape':  150,
    'banana':  10,
}

# printing a whole dictionary
print (fruit_price)

# looping dictionary
print ('fruit prices 1:')
for fruit in fruit_price:
    print (' ', fruit, ':', fruit_price[fruit])

print ('fruit prices 2:')
for fruit in fruit_price.keys ():
    print (' ', fruit, ':', fruit_price[fruit])
    
print ('fruit prices 3:')
for fruit, price in fruit_price.items ():
    print (' ', fruit, ':', price)

実行すると次のようになる。
% ./test_dictionary_2.py 
{'durian': 200, 'cherry': 100, 'apple': 50, 'grape': 150, 'banana': 10}
fruit prices 1:
  durian : 200
  cherry : 100
  apple : 50
  grape : 150
  banana : 10
fruit prices 2:
  durian : 200
  cherry : 100
  apple : 50
  grape : 150
  banana : 10
fruit prices 3:
  durian : 200
  cherry : 100
  apple : 50
  grape : 150
  banana : 10

辞書のデータをキーでソートする

辞書のデータをキーでソートする方法は以下の通り。

#!/usr/pkg/bin/python3.9

# initialisation of a dictionary
fruit_price = {
    'durian': 200,
    'cherry': 100,
    'apple':   50,
    'grape':  150,
    'banana':  10,
}

# printing a whole dictionary
print (fruit_price)

# looping dictionary (sort by keys)
print ('fruit prices 1:')
for fruit in sorted (fruit_price):
    print (' ', fruit, ':', fruit_price[fruit])

print ('fruit prices 2:')
for fruit in sorted (fruit_price.keys ()):
    print (' ', fruit, ':', fruit_price[fruit])
    
print ('fruit prices 3:')
for fruit, price in sorted (fruit_price.items ()):
    print (' ', fruit, ':', price)

実行してみる。
% ./test_dictionary_3.py 
{'durian': 200, 'cherry': 100, 'apple': 50, 'grape': 150, 'banana': 10}
fruit prices 1:
  apple : 50
  banana : 10
  cherry : 100
  durian : 200
  grape : 150
fruit prices 2:
  apple : 50
  banana : 10
  cherry : 100
  durian : 200
  grape : 150
fruit prices 3:
  apple : 50
  banana : 10
  cherry : 100
  durian : 200
  grape : 150

辞書のデータを値でソートする

辞書のデータを値でソートする方法は以下の通り。

#!/usr/pkg/bin/python3.9

# initialisation of a dictionary
fruit_price = {
    'durian': 200,
    'cherry': 100,
    'apple':   50,
    'grape':  150,
    'banana':  10,
}

# printing a whole dictionary
print (fruit_price)

# looping dictionary (sort by values)
print ('fruit prices 1:')
for fruit, price in sorted (fruit_price.items (), key=lambda x: x[1]):
    print (' ', fruit, ':', price)

print ('fruit prices 2:')
for fruit in sorted (fruit_price, key=fruit_price.get):
    print (' ', fruit, ':', fruit_price[fruit])

実行してみる。
% ./test_dictionary_4.py
{'durian': 200, 'cherry': 100, 'apple': 50, 'grape': 150, 'banana': 10}
fruit prices 1:
  banana : 10
  apple : 50
  cherry : 100
  grape : 150
  durian : 200
fruit prices 2:
  banana : 10
  apple : 50
  cherry : 100
  grape : 150
  durian : 200

辞書の辞書 (多次元辞書) の使い方

辞書の辞書の使い方は以下の通り。

#!/usr/pkg/bin/python3.9

# initialisation of a dictionary of dictionary
data = {
    'Taiwan': {'capital': 'Taipei', 'climate': 'tropical', 'currency': 'NT'},
    'Japan': {'capital': 'Tokyo', 'climate': 'temperate', 'currency': 'Yen'},
    'Korea': {'capital': 'Seoul', 'climate': 'temperate', 'currency': 'Won'},
    'Vietnam': {'capital': 'Hanoi', 'climate': 'tropical', 'currency': 'Dong'},
    'Thailand': {'capital': 'Bangkok', 'climate': 'tropical', 'currency': 'Baht'},
    'Malaysia': {'capital': 'Kuala Lumpur', 'climate': 'tropical', 'currency': 'Ringgit'},
    'Singapore': {'capital': 'Singapore', 'climate': 'tropical', 'currency': 'Dollar'},
    'Indonesia': {'capital': 'Jakarta', 'climate': 'tropical', 'currency': 'Rupiah'},
}

# printing an element of a dictionary
print ("Capital of Malaysia =", data['Malaysia']['capital'])
print ("Currency of Thailand =", data['Thailand']['currency'])

実行すると以下のようになる。
% ./test_dictionary_5.py
Capital of Malaysia = Kuala Lumpur
Currency of Thailand = Baht

辞書の辞書にデータを追加する方法

辞書の辞書にデータを追加する方法は以下の通り。

#!/usr/pkg/bin/python3.9

# initialisation of a dictionary of dictionary
data = {}

data['Taiwan'] = {}
data['Taiwan']['capital']  = 'Taipei'
data['Taiwan']['climate']  = 'tropical'
data['Taiwan']['currency'] = 'NT'

data['Japan'] = {}
data['Japan']['capital']   = 'Tokyo'
data['Japan']['climate']   = 'temperate'
data['Japan']['currency']  = 'Yen'

# printing a dictionary
print ("data['Taiwan'] =", data['Taiwan'])
print ("data['Japan']  =", data['Japan'])
print ("data['Japan']['climate'] =", data['Japan']['climate'])

実行すると次のようになる。
% ./test_dictionary_6.py
data['Taiwan'] = {'capital': 'Taipei', 'climate': 'tropical', 'currency': 'NT'}
data['Japan']  = {'capital': 'Tokyo', 'climate': 'temperate', 'currency': 'Yen'}
data['Japan']['climate'] = temperate


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