1.sorted(d.items(),key=lambda item:item[1] ,reverse=False)
注意得到的是个list，要得到字典前面加dict()
>>> d={
"one":
45,
"two":
24,
"three":
78,
"four":
98}
>>> d.items()
dict_items([(
'one',
45), (
'two',
24), (
'three',
78), (
'four',
98)])
>>> sorted(d.items(),key=
lambda item:item[
1],reverse=
False)
[(
'two',
24), (
'one',
45), (
'three',
78), (
'four',
98)]
>>> dict(sorted(d.items(),key=
lambda item:item[
1],reverse=
False) )
{
'two':
24,
'one':
45,
'three':
78,
'four':
98}
2.sorted()传入dict时没有加items，则默认比较的是dict的key，所以在key=function()参数x也是dict的key
from collections
import Counter
x = Counter({
'a':
5,
'b':
3,
'c':
7})
sorted(x)
>>[
'a',
'b',
'c']
sorted(x.items())
>>[(
'a',
5), (
'b',
3), (
'c',
7)]
tf_counter = Counter(gen_tf(data))
df_counter = Counter(gen_df(data))
vocab = sorted(df_counter,
key=
lambda x: (df_counter.get(x),tf_counter.get(x)),
reverse=
True)
