How to parse a json list?

Question

I've a json list:

tcp_packet = {'green': [], 'red': [{'arm_id': 2, 'pptl_id': [1]}, {'arm_id': 1, 'pptl_id': [1]}]}

I need to check whether arm_id exists in 'red' or not?

currently i have to loop around tcp_packet['red'] to find out whether arm_id = 2 exists or not?

for i in tcp_packet[color]:
   if '2' in i.keys():
       do something

is there a one-line solution to this?

Answer 1

do_something() if 2 in [x.get('arm_id') for x in tcp_packet['red']] else None

Answer 2

It's a bit unclear from your question, but is this what you are looking for?

>>> tcp_packet = {'green': [], 'red': [{'arm_id': 2, 'pptl_id': [1]}, {'arm_id': 1, 'pptl_id': [1]}]}
>>> any((('arm_id', 2) in i.iteritems()) for i in tcp_packet['green'])
False
>>> any((('arm_id', 2) in i.iteritems()) for i in tcp_packet['red'])
True