使pandas dataframe group by count具有列名

在Python3.6和Pandas0.19.0中,有一个数据帧“df”

id
abc
abc
def

SELECT id, COUNT(1) AS id_count FROM table group by id

理想回报:

id  id_count
abc 2
def 1

我试过:

print (df.groupby(['id'])['id'].count())

id
abc 2
def 1

print (df.groupby(['id'])['id'].transform('count'))

0    2
1    1

有什么想法吗?谢谢您!