Dictionary in python programming language

Python dictionary

In this tutorial, we will discuss the dictionary in the python programming language.

Dictionary is a special type of variable in python. It is an unordered collection of items, it has a pair of items, key and value. When creating the dictionary, we can place items inside of the dictionary using  curly braces{} and separated by a comma.

Every item has a key and the corresponding value expressed as a pair key: value

How to create the dictionary

ProgrammingLanguages={}
ProgrammingLanguages[“php”]=”Hyper text Preprocessor”
ProgrammingLanguages[“htm”]=”Hyper text markup language”
ProgrammingLanguages[“css”]=”cascading style sheet”
ProgrammingLanguages[“js”]=”Java script”

How to accessing Dictionary

How to print all of element of dictionary

print(ProgrammingLanguages) //print all element of dictionary

Output

{‘php’: ‘Hyper text Preprocessor’, ‘html’: ‘Hyper text markup language’, ‘css’: ‘cascading style sheet’, ‘js’: ‘Java script’}

Print  every element of using name instead index value or key value

Output                                   //print every element of dictionary using keys

Hypertext Preprocessor
Hypertext markup language
cascading style sheet
Java script

How to update an item of dictionary

If we want to update items to the dictionary, we can use an assignment operator. An example is given below

When the above code is executed, it produces the following results

{'age': 45, 'name': 'saman'} // before update
{'age': 34, 'name': 'saman'} //after update
How to add the item of dictionary

If we want to add items to the dictionary, we can use the assignment operator. Example is given below

When the above code is executed, it produced the following results

{'age': 45, 'name': 'saman'}  // before add
{'age': 45, 'name': 'saman', 'address': 'Jaffna'} //after add

How to remove the item of dictionary

If we want to remove items from the dictionary, we can use pop() operator. Example is given below

{'age': 45, 'name': 'saman', 'address': 'colombo'}

45

{'name': 'saman', 'address': 'colombo'}

{'age': 45, 'name': 'saman', 'address': 'colombo'}

('age', 45)

{'name': 'saman', 'address': 'colombo'}

{1: 1, 2: 3, 3: 6, 4: 10, 5: 15}
{1: 1, 2: 3, 3: 6, 5: 15}

{}