Page 425 - Computer Science V2.0 Class 11

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('Sanskrit', 78) ('English', 185) ('Maths', 88) ('Hindi', 90)
Fig 14.2 shows the keys, values, and items for the dictionary subjects.

Fig 14.2: key part, value part, and items of object subjects of type dict
● myDict.update(): The method update() adds all key-value pairs of another dictionary in an existing
dictionary.
Example:
>>> loginDetails = {'Aryan':'a7@101', 'Sunpreet':'sun@102', 'Anthony':'ant@103' }
>>> moreUsers = {'Samantha':'sam@104','Venkatesh':'ven@105'}
>>> loginDetails.update(moreUsers)
>>> print(loginDetails)
{'Aryan': 'a7@101', 'Sunpreet': 'sun@102', 'Anthony': 'ant@103', 'Samantha': 'sam@104',
'Venkatesh': 'ven@105'}
● myDict.pop(myKey): The method pop() returns value (say, myValue) for the key (myKey)passed as an
argument, and removes the item (myKey:myValue) with the specified key from the dictionary.
Example:

>>> months = {3:'March', 11:'November', 12: 'December', 1:'January'}
>>> months.pop(11)
'November'
>>> months
{3: 'March', 12: 'December', 1: 'January'}
● myDict.popitem(): The method popitem() removes the last inserted item (key-value pair) from the
dictionary. In Python versions prior to 3.7, this method removes a random item.
Example:
>>> months = {3:'March', 11:'November', 12: 'December', 1:'January'}
>>> months.popitem()
(1, 'January')
>>> months
{3: 'March', 11: 'November', 12: 'December'}
14.5.1 del Operator

The Python keyword operator del can also be used to remove key-value pair(s) from a dictionary.
Example:

>>> months = {3:'March', 11:'November', 12: 'December', 1:'January'}
>>> del months[11]

Dictionaries 411