What is Python Dictionary? How to Create Dictionary in Python?
What is Python Dictionary?
A dictionary in Python is an unordered group or collection of data values that may be used to store data values in the same way that a map can.
Unlike other data types, which can only carry a single value as an element, dictionaries can hold a key-value pair. The dictionary includes a key-value pair to make it more efficient.
How to Create a Dictionary in Python?
A dictionary is built in Python by enclosing a succession of entries in curly braces and separating them with a comma.
Dictionary stores a pair of values, one of which is the Key and the other is the Key-value pair element. In a dictionary, values can be of any data type and can be replicated, but keys can’t be copied and must be immutable.
Note: Dictionary keys are case-sensitive. Therefore two keys with the same name but different cases will be interpreted differently.
# Creating a Dictionary
# with Integer Keys
myDict = {1: 'WSC', 2: 'For', 3: 'WSC'}
print(myDict)
# Creating a Dictionary
# with Mixed keys
myDict = {'Name': 'WSC', 1: [1, 2, 3]}
print("\nDictionary with Mixed Keys: ")
print(myDict)
Output:
You can also create the dictionary with built-in function dict(). To create empty dictionary, use curly bracket {}.
# Creating an empty Dictionary
myDict = {}
print("Empty Dictionary: ")
print(myDict)
# Creating a Dictionary
# with dict() method
myDict = dict({1: 'WSC', 2: 'For', 3:'WSC'})
print("\nDictionary with the use of dict(): ")
print(myDict)
# Creating a Dictionary
# with each item as a Pair
myDict = dict([(1, 'WSC'), (2, 'For')])
print("\nDictionary with items as pair: ")
print(myDict)
Output:
How to Access Data From a Dictionary?
To get to the things in a dictionary, look up the key name. Inside square brackets, the key can be used.
Dict = {1: 'WSC', 'name': 'For', 3: 'WSC'}
# accessing a element using key
print("Accessing a element using key:")
print(Dict['name'])
# accessing an element using key
print("Accessing an element using key:")
print(Dict[1])
Output:
There is also a get() function that may be used to obtain an element from a dictionary.
# Creating a Dictionary
Dict = {1: 'WSC', 'name': 'For', 3: 'WSC'}
# accessing an element using get()
# method
print("Accessing an element using get:")
print(Dict.get(3))
Output:
How to Update data in Python Dictionary?
The dictionary is updated with items from another dictionary object or an iterable of key/value pairs using the update() function.
Example:
marks = {'Physics':67, 'Maths':87}
internal_marks = {'Practical':48}
marks.update(internal_marks)
print(marks)
Output: