Python Dictionary –

Lakhan  Balmiki 

 

Dictionary is one of the most prominent data structure of Python. Whether you are working on Machine Learning dataset or any RDBM’s or NoSQL databases, dictionary is going to be in frequent use to make your code easier and efficient.

 

What is Dictionary in Python..??

Dictionaries are used to store data values in key/value pairs.A dictionary is a collection which is ordered*, changeable and do not allow duplicates.

Dictionaries are written with curly brackets, and have keys and values:

Create and print a dictionary:

 

thisdict = {
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964
}
print(thisdict)

 

Dictionary Items.

Dictionary items are ordered, changeable, and does not allow duplicates.

Dictionary items are presented in key:value pairs, and can be referred to by using the key name.

Ordered or Unordered?

When we say that dictionaries are ordered, it means that the items have a defined order, and that order will not change.

Unordered means that the items does not have a defined order, you cannot refer to an item by using an index.

Changeable.

Dictionaries are changeable, meaning that we can change, add or remove items after the dictionary has been created.

Duplicates Not Allowed.

Dictionaries cannot have two items with the same key:

Example:

Duplicate values will overwrite existing values:

 

thisdict = {
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964,
  "year": 2020
}
print(thisdict)