Value Verification in Python Dictionary

Question

Please advise what is the correct way to verify if key x is stored in a dictionary dict. and if it is, set a value check to True and otherwise it will be set to False.

check = True

try :
   y = d.x
except KeyError as e
   check = False

Or is it the right way to do one the following?

1. check = dict.contains(x)
2. check = dict.has_key(x)
3. check = x in dict
4. check = x.is_elem(dict)

Answer 1

The most common approach seems to be x in d