Servlet-HttpSession介面
阿新 • • 發佈:2021-01-10
技術標籤:Python_Basepython
簡介
字典是一種可變容器模型,且可儲存任意型別物件,字典的每個鍵值 key=>value
對用冒號:
分割,每個鍵值對之間用逗號 ,
分割,整個字典包括在花括號{}
中 ,如:
object = {
'color': 'yellow',
'size': 'big'
}
print(object['color'])
print(object['size'])
新增鍵值對
object['age'] = 18
object['sex'] = 'man'
print(object)
建立一個空字典
object = {} object['color'] = 'yellow' object['size'] = 'big' print(object)
修改字典中的值
object['color'] = 'black'
print(object)
刪除鍵值對
object = {'color': 'black', 'age': 18}
del object['color']
print(object)
遍歷鍵值對
user = {
'username': 'coisini',
'age': '18',
'sex': 'man'
}
for key,value in user.items():
print('key:' + key)
print('value:' + value)
遍歷所有鍵值
use_languages = { 'one_user': 'python', 'two_user': 'c', 'three_user': 'ruby', 'four_user': 'python' } for key in use_languages.keys(): print('key:' + key) print('value:' + use_languages[key]) if key == 'one_user': print('one_user is in use_languages')
use_languages.key() 簡寫為use_languages
if 'four_user' in use_languages:
print('four_user is in use_languages')
順序遍歷所有鍵值
for name in sorted(use_languages.keys()):
print(name.title())
遍歷字典中的所有值
for language in use_languages.values():
print(language.title())
使用集合(set)剔除重複項
for language in set(use_languages.values()): print(language.title())
列表字典巢狀
one_user = {'color': 'black', 'age': 5}
two_user = {'color': 'white', 'age': 10}
three_user = {'color': 'yellow', 'age': 15}
users = [one_user, two_user, three_user]
for user in users:
print(user)
字典列表巢狀
user = {
'username': 'coisini',
'languages': ['Java', 'Python']
}
for language in user['languages']:
print('\t' + language)
字典字典巢狀
users = {
'coisini': {
'name': 'coisini',
'age': 18,
'location': 'China'
},
'maggieq': {
'name': 'maggieq',
'age': '22',
'location': 'Canada'
}
}
for username, userinfo in users.items():
print('\nusername:' + username)
for key, val in users[username].items():
print('\tkey:' + str(key))
print('\tval:' + str(val))