python基础（五）

#字典，访问字典中的值
alien_0 = {'color':'green','points':5}
print(alien_0['color'])
print(alien_0['points'])

green
5

#将值存储在变量中new_points中
new_points = alien_0['points']
print("You just earned " + str(new_points) + " points!")

You just earned 5 points!

#添加键-值对；指定字典名，用方括号括起的键和相关联的值
alien_0 = {'color':'green','points':5}
print(alien_0)
alien_0['x_position'] = 0
alien_0['y_position'] = 25
print(alien_0)

{'color': 'green', 'points': 5}
{'color': 'green', 'points': 5, 'x_position': 0, 'y_position': 25}

#先创建一个空字典
alien_0 = {}
alien_0['color'] = 'green'
alien_0['points'] = 5
print(alien_0)

{'color': 'green', 'points': 5}

#修改字典中的值
alien_0 = {'color':'green'}
print("The alien is " + alien_0['color'] + ".")

The alien is green.

alien_0 = {'color':'yellow'}
print("The alien is now " + alien_0['color'] + ".")

The alien is now yellow.

#创建一个字典
alien_0 = {'x_position':0, 'y_position':25, 'speed':'medium'}
print("Original x-position: " + str(alien_0['x_position']))

Original x-position: 0

if alien_0['speed'] == 'slow':
    x_increment = 1
elif alien_0['speed'] == 'medium':
    x_increment = 2
else:
    x_increment = 3

alien_0['x_position'] = alien_0['x_position'] + x_increment#通过修改外星人字典中的值，可改变外星人的行为。

print(str(alien_0['x_position']))

2

alien_0['x_position']

2

#删除键值对
alien_0 = {'color':'green','points':5}
print(alien_0)
del alien_0['points']
print(alien_0)

{'color': 'green', 'points': 5}
{'color': 'green'}

#由类似对象组成的字典，注意这个地方的逗号！
fav_flo = {
    'baba':'hehua',
    'mama':'meihua',
    'jingjing':'xiangrikui'
}

print("Jingjing's favorite flower is " + fav_flo['jingjing'].title() + ".")

Jingjing's favorite flower is Xiangrikui.

#遍历字典
fav_flo = {
    'baba':'hehua',
    'mama':'meihua',
    'jingjing':'xiangrikui'
}
for key, value in fav_flo.items():
    print("\nKey:" + key)
    print("Value:" + value)

Key:baba
Value:hehua

Key:mama
Value:meihua

Key:jingjing
Value:xiangrikui

#遍历字典中所有键值对
for key, value in fav_flo.items():
    print("\n" + key.title() + "'s favorite flower is " + value.title() + "!")

Baba's favorite flower is Hehua!

Mama's favorite flower is Meihua!

Jingjing's favorite flower is Xiangrikui!

#遍历字典中所有键
for key in fav_flo.keys():
    print(key)

baba
mama
jingjing

ai = ['baba','mama']
for key in fav_flo.keys():
    print(key.title())

Baba
Mama
Jingjing

favorite_languages = {
    '1':'python',
    '2':'c',
    '3':'ruby',
    '4':'python',
}
friends = ['1', '2']
for name in favorite_languages.keys():
    print(name.title())
#bug
for name in friends:
    print(name.title())

1
2
3
4
1
2

for name in friends:
    print("Hi" + name.title() + ", I see your favorite languages is " + favorite_languages[name].title() + "!")

Hi1, I see your favorite languages is Python!
Hi2, I see your favorite languages is C!

favorite_languages['2'].title()

'C'

if '5' not in favorite_languages.keys():
    print("ahhaha")

ahhaha

child_age = {
    'yue':'12',
    'zai':'10',
    'lu':'19'
}

for name, age in child_age.items():
    print(name.title() + age.title())

Yue12
Zai10
Lu19

didi = ['zai', 'lu']
for name in didi:
    print("\n" + name.title() + child_age[name].title())

Zai10

Lu19

#按顺序遍历字典中的所有键
favorite_languages = {
    '1':'python',
    '2':'c',
    '3':'ruby',
    '4':'python',
}
for name in sorted(favorite_languages.keys()):
    print(name.title() + "hihi")

#遍历字典中的所有值
favorite_languages = {
    '1':'python',
    '2':'c',
    '3':'ruby',
    '4':'python',
}
for language in favorite_languages.values():
    print(language.title())

Python
C
Ruby
Python

#遍历唯一的值
for language in set(favorite_languages.values()):
    print(language.title())

C
Python
Ruby

#嵌套，在列表中嵌套字典，或者在字典中嵌套表
#字典列表
alien_0 = {'color':'green', 'points':5}
alien_1 = {'color':'red', 'points':4}
alien_2 = {'color':'blue', 'points':3}

aliens = [alien_0, alien_1, alien_2]

for alien in aliens:
    print(alien)

{'color': 'green', 'points': 5}
{'color': 'red', 'points': 4}
{'color': 'blue', 'points': 3}

aliens = []
for alien_number in range(30):
    new_alien ={'color':'green', 'points':5, 'speed':'slow'}
    aliens.append(new_alien)

for alien in aliens[:5]:
    print(alien)
print("...")
print("Total number of aliens:" + str(len(aliens)))

{'color': 'green', 'points': 5}
{'color': 'red', 'points': 4}
{'color': 'blue', 'points': 3}
{'color': 'green', 'points': 5, 'speed': 'slow'}
{'color': 'green', 'points': 5, 'speed': 'slow'}
...
Total number of aliens:33

witchs = []
for witch_number in range(30):
    new_witch = {'color':'green', 'points':5, 'speed':'slow'}
    witchs.append(new_witch)

for witch in witchs[:5]:
    print(witch)

{'color': 'green', 'points': 5, 'speed': 'slow'}
{'color': 'green', 'points': 5, 'speed': 'slow'}
{'color': 'green', 'points': 5, 'speed': 'slow'}
{'color': 'green', 'points': 5, 'speed': 'slow'}
{'color': 'green', 'points': 5, 'speed': 'slow'}

for witch in witchs[0:3]:
    if witch['color'] == 'green':
        witch['color'] = 'yellow'
        witch['speed'] = 'medium'
        witch['points'] = 10

for witch in witchs[:5]:
    print(witch)

{'color': 'yellow', 'points': 10, 'speed': 'medium'}
{'color': 'yellow', 'points': 10, 'speed': 'medium'}
{'color': 'yellow', 'points': 10, 'speed': 'medium'}
{'color': 'green', 'points': 5, 'speed': 'slow'}
{'color': 'green', 'points': 5, 'speed': 'slow'}

#在字典中存储列表
pizza = {
    'crust': 'thick',
    'toppings': ['mushroom', 'extra cheese'],
}

print("You order a " + pizza['crust'] + "-crust pizza" + "with the following toppings")

for topping in pizza['toppings']:
    print("\t" + topping)

You order a thick-crust pizzawith the following toppings
	mushroom
	extra cheese

aaa_111 = {
    'a':['1', '2'],
    'b':['3', '4'],
    'c':['5', '4'],
}
for key, values in aaa_111.items():
    print("\n" + key.title() + " hahah")
    for value in values:
        print("\t" + value.title())

A hahah
	1
	2

B hahah
	3
	4

C hahah
	5
	4

#在字典中存储字典
users = {
    'aeinstein':{
        'aa':'aaa',
        'bb':'bbb',
        'cc':'ccc',
        },
     'mcurie':{
        'aa':'ddd',
        'bb':'fff',
        'cc':'ggg',
        },
}
    

for username, user_info in users.items():
    print("\nUsername: " + username)
    full_name = user_info['aa'] + " " + user_info['bb']
    location = user_info['cc']
    
    print(full_name)
    print(location)

Username: aeinstein
aaa bbb
ccc

Username: mcurie
ddd fff
ggg