Aggregating data in Python Pandas

Question

I am working on dataframe like this in Python Pandas:

import pandas as pd
df = pd.DataFrame({'date_time':['2019-03-29 16:04','2019-03-20 20:31' , '2019-03-26 21:02' , '2019-03-26 21:05' , '2019-03-29 16:04','2019-04-01 19:40'  , '2019-04-01 19:41'],
                   
             'item':['bed',  'lamp', 'candle', 'chair', 'bed',  'candle', 'lamp'],
             'location' :['home', 'home', 'home',   'home',  'home', 'home',   'home' ],
             'status'   :['new',  'used', 'used',   'new',   'new',  'used',   'new' ]})

df

and I am trying to create a summary like this dataframe:

# Expected output
# The number of records for each date_time and item, sorted by date_time

# date_time        item   count
# 2019-03-20 20:31 lamp   1
# 2019-03-26 21:02 candle 1
# 2019-03-26 21:05 chair  1
# 2019-03-29 16:04 bed    2
# 2019-04-01 19:40 candle 1
# 2019-04-01 19:41 lamp   1

I tried different aggregation methods but I could not create this dataframe.