Answers for ". If the key is not present in the dictionary it should be added with value 0. in python"

python dictionary default value if key doesn't exist

value = d.get(key)				# Null
value = d.get(key, "empty")		# empty

how to check if a key is present in python dictionary

dict = { "How":1,"you":2,"like":3,"this":4}
key = "this"
if key in dict.keys():
    print("present")
    print("value =",dict[key])
else:
    print("Not present")