dict(‘name‘:‘123‘)

dict.get(‘name‘) 使用get命令查字典，當字典內無該元素不會報錯

dict(‘name‘:‘123‘)

dict(‘age‘),返回程序出錯

dict(‘name‘:‘123‘)

dict[‘age‘] = ‘13‘]若沒有該主鍵得到

{‘name‘:‘demonlg‘,‘age‘:‘13‘}

若有該主鍵將age對應的元素修改為13

a = {‘name‘:‘demonlg‘,‘123131‘:‘2222‘,‘32313‘:‘2222‘,‘4343‘:‘24‘}
del a[‘1233‘]
print(a)

File "E:/python/day1/set.py", line 21, in <module>

del a[‘1233‘]

KeyError: ‘1233‘

Process finished with exit code 1

a = {‘name‘:‘demonlg‘,‘123131‘:‘2222‘,‘32313‘:‘2222‘,‘4343‘:‘24‘}
a.pop(‘123131‘)
print(a)

{‘name‘: ‘demonlg‘, ‘32313‘: ‘2222‘, ‘4343‘: ‘24‘}

Process finished with exit code 0

a = {‘name‘:
 
‘demonlg‘}
b = {‘2222‘:‘32313‘}
a.update(b)
print(a)

{‘name‘: ‘demonlg‘, ‘2222‘: ‘32313‘}

a = {‘name‘:‘demonlg‘}
b = {‘2222‘:‘32313‘}
a.clear()
print(a)

得到：{}

a = {‘name‘:‘demonlg‘}
a.setdefault(‘2222‘,‘32313‘)
print(a)

得到{‘name‘: ‘demonlg‘, ‘2222‘: ‘32313‘}

c = dict.fromkeys([‘name‘,‘age‘‘man‘])
print(a,c)

{‘name‘: None, ‘ageman‘: None}