Trying to check if value exists in json

Question

I've been trying to create a script that checks for if a value exists in a json file but I keep getting a error that I don't understand and its the same no matter how I rewrite. my questions are what is the error and how could I fix it? code snippet:

with open('json_file.json') as f:
     data = json.load(f)
for i in data:
   if i['hosts'] in data:
      print("it found it")

error message:

Ignoring exception in command myprofile:
Traceback (most recent call last):
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/core.py", line 85, in wrapped
    ret = await coro(*args, **kwargs)
  File "main.py", line 64, in myprofile
    if i['hosts'] in data:
KeyError: 'hosts'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/bot.py", line 902, in invoke
    await ctx.command.invoke(ctx)
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/core.py", line 864, in invoke
    await injected(*ctx.args, **ctx.kwargs)
  File "/opt/virtualenvs/python3/lib/python3.8/site-packages/discord/ext/commands/core.py", line 94, in wrapped
    raise CommandInvokeError(exc) from exc
discord.ext.commands.errors.CommandInvokeError: Command raised an exception: KeyError: 'hosts'

Answer 1

Try using i.get('hosts', None) instead of i['hosts'] .

For example if your json file looks like this {'field1': {'someotherfield': 'xxxx'}, 'field2': {'hosts': 'host1'}}

when the statement for i in data: runs it loops through field1 & field2 . The statement i['hosts'] requires every field (ie) field1, field2 in our case to have a key called as hosts . If some field doesn't have that key it raises KeyError . Instead use i.get('hosts', None) it would firstly check for the key named hosts , if it is not present it simply returns None.

PS: If you are working with a simple dictionary, then @JaniniRami's solution should work fine for you, if you are working with a nested dictionary or json like dictionary then my solution would do it for you.

Answer 2

found =  "hosts" in data 

print(found)

Found will return either True or False at this case.

Answer 3

Only one other answer seemed to answer your 1st question. The error is that the key was not found, so it raises KeyError . While there are multiple ways to fix this, the probably easiest (subjective) to understand is this code snippet:

try:
    data = i['hosts']
except KeyError:
    #notfound