How to check if Key Exists in Python Dictionary?

To check if a Python Dictionary contains a specific key or not you can make use of the if statement with a in keyword,

# Python Dictionary containing
# names of cities

def check_for_key(cities,city_name):
  if city_name in cities:
    print("City {} is available in dictionary cities..".format(city_name))
  else:
    print("City {} is not available in dictionary cities..".format(city_name))

cities = {'Tokyo','Paris','New York', 'Mumbai', 'London'}

check_for_key(cities,'London')
check_for_key(cities,'Austin')

City London is available in dictionary cities..
City Austin is not available in dictionary cities..