1. fromkeys(seq,value) :- This method is used to declare a new dictionary from the sequence mentioned in its arguments. This function can also initialize the declared dictionary with “value” argument.
2. update(dic) :- This function is used to update the dictionary to add other dictionary keys.
# Python code to demonstrate working of # fromkeys() and update() # Initializing dictionary 1 dic1 = { 'Name' : 'Nandini', 'Age' : 19 } # Initializing dictionary 2 dic2 = { 'ID' : 2541997 } # Initializing sequence sequ = ('Name', 'Age', 'ID') # using update to add dic2 values in dic 1 dic1.update(dic2) # printing updated dictionary values print ("The updated dictionary is : ") print (str(dic1)) # using fromkeys() to transform sequence into dictionary dict = dict.fromkeys(sequ,5) # printing new dictionary values print ("The new dictionary values are : ") print (str(dict)) |
Output:
The updated dictionary is :
{'Age': 19, 'Name': 'Nandini', 'ID': 2541997}
The new dictionary values are :
{'Age': 5, 'Name': 5, 'ID': 5}
3. has_key() :- This function returns true if specified key is present in the dictionary, else returns false.
4. get(key, def_val) :- This function return the key value associated with the key mentioned in arguments. If key is not present, the default value is returned.
# Python code to demonstrate working of # has_key() and get() # Initializing dictionary dict = { 'Name' : 'Nandini', 'Age' : 19 } # using has_key() to check if dic1 has a key if dict.has_key('Name'): print ("Name is a key") else : print ("Name is not a key") # using get() to print a key value print ("The value associated with ID is : ") print (dict.get('ID', "Not Present")) # printing dictionary values print ("The dictionary values are : ") print (str(dict)) |
Output:
Name is a key
The value associated with ID is :
Not Present
The dictionary values are :
{'Name': 'Nandini', 'Age': 19}
5. setdefault(key, def_value) :- This function also searches for a key and displays its value like get() but, it creates new key with def_value if key is not present.
# Python code to demonstrate working of # setdefault() # Initializing dictionary dict = { 'Name' : 'Nandini', 'Age' : 19 } # using setdefault() to print a key value print ("The value associated with Age is : ",end="") print (dict.setdefault('ID', "No ID")) # printing dictionary values print ("The dictionary values are : ") print (str(dict)) |
Output:
The value associated with Age is : No ID
The dictionary values are :
{'Name': 'Nandini', 'Age': 19, 'ID': 'No ID'}
