dict={'derivative':'2','raw':'4','supervise':'machine learning','calculus':'good'}

#遍历键 key
for i in dict.keys():
  print(i)  #输出键
  print(dict[i]) #输出值
 
#遍历键 values
for i in dict.values():
  print(i)
 
#遍历键和值
for key,value in dict.items():
  print(key+": "+str(value))

lis=sorted(dict.items(),key=lambda d:d[0]) #按键来排序
lis=sorted(dict.items(),key=lambda d:d[1]) #按值来排序

if 'derivative' in dict.keys():
  print('good')
 
if 'good' in dict.values():
  print('happy')

for i in set(dict.values()):
  print(i)