Dictionary Data Type

About Dictionary

• Dictionary is an unordered collection of key-value pairs
• When we have the large amount of data, the dictionary data type is used
• Keys and values can be of any type in a dictionary
•  Items in dictionary are enclosed in the curly-braces { } and separated by commas (,)
• A colon (:) is used to separate key from value
• A key inside the square brackets [ ] is used for accessing the dictionary items
• Dictionaries are accessed via
  • The keys
  • The values
  • Items (key – value pairs)

Operations

Creating a Dictionary

Creating the dictionary with elements of different data types

Example

>>> first_dict = {1:"Apple",2:"Mango",3:"Banana"}
>>> print(first_dict)
{1: 'Apple', 2: 'Mango', 3: 'Banana'}

Indexing

Access the items of a dictionary by referring to its key name inside square brackets

Example

>>> print(first_dict[1])
Apple

Change values

Change the value of a specific item by referring to its key name

Example

>>> first_dict[2] = "orange"
>>> print(first_dict)
{1: 'Apple', 2: 'orange', 3: 'Banana'}

Printing keys

Print all key names in the dictionary one by one

Example

>>> print(first_dict.keys())
dict_keys([1, 2, 3])

Printing values

Print all values in the dictionary one by one

Example

>>> print(first_dict.values())
dict_values(['Apple', 'Mango', 'Banana'])

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