Dictionaries:

Dictionaries are collections of associated pairs of items where each pair consists of a key and a value. This key-value pair is typically written as key:value. Dictionaries are written as comma-delimited key:value pairs enclosed in curly braces.

Using a Dictionary:

It is important to note that the dictionary is maintained in no particular order with respect to the keys. The first pair added (‘Utah’: ‘SaltLakeCity’) was placed first in the dictionary and the second pair added (‘California’: ‘Sacramento’) was placed last. The placement of a key is dependent on the idea of “hashing,” Dictionaries have both methods and operators.

Operators Provided by Dictionaries in Python
Operator	Use	Explanation
[]	myDict[k]	Returns the value associated with k, otherwise its an error
In	key in adict	Returns True if key is in the dictionary, False otherwise
Del	del adict[key]	Removes the entry from the dictionary

 

 

phoneext={‘david’:1410,’brad’:1137}>>> phoneext{‘brad’: 1137, ‘david’: 1410}>>> phoneext.keys()dict_keys([‘brad’, ‘david’])>>> list(phoneext.keys())[‘brad’, ‘david’]>>> phoneext.values()dict_values([1137, 1410])>>> list(phoneext.values())[1137, 1410]>>> phoneext.items()dict_items([(‘brad’, 1137), (‘david’, 1410)])>>> list(phoneext.items())[(‘brad’, 1137), (‘david’, 1410)]>>> phoneext.get(“kent”)>>> phoneext.get(“kent”,”NO ENTRY”)

‘NO ENTRY’

• Create a Class data type called Student()
• Write two functions/methods as part of the class:
  1. addStudentInfo() – adding a student data and
  2. retrieveStudentInfo() – retrieving student information.
• Insert Three students records. Data is given below.
• Print the student data whose admission year is 2019