Can we do boolean on dictionary keys?

Question

For example i want to check whether 'a' key is in dict or not. what should i do?

so far i did this :
a = {'123':0,'445':0}
if a['567'] in a:
print('yes')
else:
print('no')

and it returns a key error

Answer 1

you should use .get method.
for example, in your dictionary
value=a.get('567','not in dictionary')

if '567' is in dictionary, value would be similar to a['567']. The second argument is returned by get method if element is not in dictionary.

Then you can apply boolean on value returned.

if value=='not in dictionary':
print('no')
else:
print('yes')

Another way which similar to what you've tried is using dictionary.keys()

ie

if '567' in a.keys():
print('yes')
else:
print('no')

Answer 2

more on what Akash said:

if '567' in a.keys():
print('yes')
else:
print('no')

in this example you don't need to write a.keys(). 'in' tests keys in a dict by default, the example can be rewritten like this:

if '567' in a:
print('yes')
else:
print('no')

you can directly write the expression in the print if you wish so

print('567' in a)