d = {'Alice': [50, 61, 66], 'Bob': [80, 61, 66], 'Candy': [88, 75, 90]}
num=0
for key in d.keys():
num=num+1
print(num)
num=0
for key in d.keys():
num=num+1
print(num)
2020-12-11
d = {
'Alice': 45,
'Bob': 60,
'Candy': 75,
'David': 86,
'Ellena': 49
}
for item in d.keys():
if item=='Alice':
print("old_score:"+str(d['Alice']))
d['Alice']=60
print(d)
'Alice': 45,
'Bob': 60,
'Candy': 75,
'David': 86,
'Ellena': 49
}
for item in d.keys():
if item=='Alice':
print("old_score:"+str(d['Alice']))
d['Alice']=60
print(d)
2020-12-11
stu=['Alice', 'Bob', 'Candy', 'David', 'Ellena']
stu[0]=stu[-1]
stu[-1]=stu[1]
stu[1]="Alice"
print(stu)
stu[0]=stu[-1]
stu[-1]=stu[1]
stu[1]="Alice"
print(stu)
2020-12-10
age = 1
if age >= 18:
print('adult')
elif age > 6:
print('teenager')
elif age > 3:
print('kid')
elif age > 0:
print('baby')
else:
print('error')
if age >= 18:
print('adult')
elif age > 6:
print('teenager')
elif age > 3:
print('kid')
elif age > 0:
print('baby')
else:
print('error')
2020-12-10
names = ['Alice', 'Bob', 'Candy', 'David', 'Ellena']
names.append('Zero')
names.insert(-1, 'Phoebe')
names.insert(-2, 'Gen')
print(names)
names.append('Zero')
names.insert(-1, 'Phoebe')
names.insert(-2, 'Gen')
print(names)
2020-12-06
如果使用old_score = d['Alice'],若不存在Alice会报错
但是old_score = d.get['Alice']就不会,只会返回None
但是old_score = d.get['Alice']就不会,只会返回None
2020-12-04