1.遍历字典dict中所有的键值对
形式如下:
for key, value in dict.items()
2.遍历字典dict中所有的键
形式如下:
for name in dict.keys()
3.遍历字典dict中所有的值
形式如下:
for val in dict.values()
综合example如下:
classes = {'math': 1,
'Chinese': 2,
'English': 3,
'physics': 4,
'history': 5}
print('打印我最初的成绩单:')
print(classes)
#del 语句
print('\n删除英语这门课:')
del classes['English']
print(classes)
#键-值
print('\n打印我的成绩单:')
for subject, grade in classes.items(): ## for key, value in dict.items()
print('my '.title() + subject.title() + ' got ' + str(grade))
#键
print('\n只打印科目:')
for subject in classes.keys(): ## for name in dict.keys()
print(subject.title())
#值
print('\n只打印成绩:')
for grade in classes.values(): ## for val in dict.values()
print(grade)
输出结果如下:
打印我最初的成绩单:
{'math': 1, 'Chinese': 2, 'English': 3, 'physics': 4, 'history': 5}
删除英语这门课:
{'math': 1, 'Chinese': 2, 'physics': 4, 'history': 5}
打印我的成绩单:
My Math got 1
My Chinese got 2
My Physics got 4
My History got 5
只打印科目:
Math
Chinese
Physics
History
只打印成绩:
1
2
4
5