Python Dictionaries

Dictionary

Dictionaries are used to store key-value pair type data. Each key and column is separated by a colon(:). To create an empty just use the curly braces{}. Keys are unique, we can’t make duplicates. If we take two keys are same then the last key value will be considered. Dictionaries are immutable. We can modify the data.

Regular Python, Regularpython, python dictionary

How to access dictionary values?

To get value from dictionary we need to use key .See the below example

student = {"name": "sairam", "Gender": "Male", "Age": 26}

print(student['name'])

print(student['Age'])

output:

sairam

How to update dictionary in python?

student = {"name": "sairam", "Gender": "Male", "Age": 26}

print('Before updating', student)

print('-----------------------------------------------')

student['name'] = 'Rajkumar'

print('After updating', student)

Output:

Before updating {'name': 'sairam', 'Gender': 'Male', 'Age': 26}

-----------------------------------------------

After updating {'name': 'Rajkumar', 'Gender': 'Male', 'Age': 26}

How to delete an element from dictionary in python?

del dict['name']; # remove entry with key 'name'

dict.clear(); # remove all entries in dict

del dict ; # delete entire dictionary

student = {"name": "sairam", "Gender": "Male", "Age": 26}

print('Before deleting', student)

print('-----------------------------------------------')

del student['name']

print('After deleting', student)

Output:

Before deleting {'name': 'sairam', 'Gender': 'Male', 'Age': 26}

-----------------------------------------------

After deleting {'Gender': 'Male', 'Age': 26}

In-Built functions in Dictionaries

Function	Description
student.clear()	It is used to remove all elements from dictionary.
student.copy()	It returns shallow copy of dictionary
student.fromkeys()	It creates a new dictionary with keys
student.get(key, default = None)	If key not found returns default value
student.has_key(key)	Returns true if key in dictionary else false
student.items()	Returns a list of dict’s tuple pairs
student.keys()	To get all keys from dictionary.
student.setdefault(key, default = None)	If key is not in dictionary it sets default key and value is None.
student.update(dict)	To update the dictionaries
student.values()	It is used to returns all values from dictionary.

Python Dictionary