Python 3 Dictionary

Definition of Python 3 Dictionary

Python 3 dictionary values data type replicated, however, keys cannot be copied and must be immutable. Keys of the dictionary is case-sensitive. With simply two curly braces, an empty dictionary with no objects can be written Values may or may not be unique within a dictionary. The keys of a dictionary must be immutable data types like texts, numbers, or tuples, whereas the contents can be of any kind.

Creating Python 3 Dictionary

• Unlike other Data Types, which can only carry elements of a single value, Dictionary can hold key-value pairs. This means that even if the name is the same, different cases of Key will be interpreted differently.

The below example shows creating python 3 dictionaries are as follows.

1) In the below example we have created python 3 dictionaries with integer and mixed keys.

Code:

# Creating dictionary by using integer Keys
Dic = {11: 'Python', 2: 'Dic', 3: 'Dictionary'}
print("\nCreating dictionary by using integer Keys: ")
print(Dic)
# Creating dictionary by using mixed keys
Dic = {'Name': 'Python', 1: [1, 2, 3, 4]}
print("\nCreating dictionary by using mixed keys: ")
print(Dic)

2) In the below example we are creating an empty dictionary and also creating a dictionary by using dict() method.

Code:

# Creating empty Dictionary by using dict method.
Dict = {}
print ("Creating Empty Dictionary: ")
print (Dict)
# Creating dictionary by using dict method.
Dict = dict ({1: 'Python', 2: 'dict', 3:'dictionary'})
print (Dict)

• In the above example we have created an empty dictionary without passing any values of keys and pairs.

3) In the below example we are creating a nested dictionary are as follows.

Code:

# Example to create a Nested Dictionary by using python 3.

Dict = {1: 'Python', 2: 'Dictionary',
3:{'A' : 'Welcome', 'B' : 'To', 'C' : 'Python'}}
print (Dict)

Python 3 dictionary access

• To get to the things in a dictionary, look up the key name. Inside square brackets, the key can be utilized.

1) In the below example we are accessing elements by using keys are as follows.

Code:

# Create dictionary by using python 3
Dict = {1: 'Python', 'name': 'dictionary', 3: 'dict'}
# accessing an element from dictionary by using key
print ("Access an element by using key:")
print (Dict ['name'])
print (Dict [1])

2) In the below example we are accessing elements from the python 3 dictionaries by using the get method are as follows.

Code:

# Create dictionary by using python 3
Dict = {1: 'Python', 'name': 'dictionary', 3: 'dict'}
# accessing an element from dictionary by using get method
print ("Access an element by using get method:")
print (Dict.get (3))
print (Dict.get (1))

3) In the below example we are accessing elements from python 3 by using a nested dictionary are as follows.

Code:

# Create dictionary by using python 3
Dic = {'Dic1': {1: 'Python'},
'Dic2': {'Name': 'Dictionary'}}
# accessing an element from dictionary by using key
print (Dic ['Dic1'])
print (Dic ['Dic1'][1])
print (Dic ['Dic2']['Name'])

Python 3 dictionary Elements

• The addition of elements in Python Dictionary can be accomplished in a variety of ways. By defining value together with the key, such as Dict [Key] = ‘Value,’ we can also add a single value to the python 3 dictionaries.
• The built-in update method can be used to replace an existing value in a Dictionary. An existing Dictionary can also have nested key values added.
• If the key-value pair exists, the given value is updated, otherwise, a new Key is created with the value.
• The elements of a dictionary are organized, changeable, and duplicates are not allowed. The key name can be used to refer to dictionary components that are given in key-value pairs.
• When we state that our dictionary is in order, we’re referring to the fact that the entries are in a specific sequence that will not alter. Unordered objects don’t have a set order, thus we can’t use an index to find them.

Python 3 Dictionary Functions

Below are the functions available are as follows.

1) Len –

• This function gives us the total length of the dictionary. The length is equal to the number of elements from the dictionary.
• The below example shows len functions in python are as follows.

Code:

Dic = {'Python': 18,'dict':12,'dictionary':22,'python':25}
print ("Length : %d" % len (Dic))

2) Str –

• This function produces the printable string are as follows.

Code:

Dic = {'Python': 18,'dict':12}
print (str (Dic))

3) Type –

• This function returns the type of a variable is as follows.

Code:

Dic = {'Python': 18,'dict':12}
print (type (Dic))

Python 3 Dictionary Method

Below is the method available as follows.

1) Copy – This method returns a shallow copy of the dictionary.

Dic = {1: 'Python', 'name': 'dictionary'}
Dic.copy()
print("copying Dictionary: ")
print(Dic)

2) Clear – This method will delete all the items from the dictionary.

Dic = {1: 'Python', 'name': 'dictionary'}
Dic.clear()
print("\nDeleting Dictionary: ")
print(Dic)

3) Pop – This method removes and returns element from the dictionary.

Dic = {1: 'Python', 'name': 'dictionary'}
pop_ele = Dic.pop(1)
print('\nDic after deletion: ' + str(Dic))
print('poped key is: ' + str(pop_ele))

4) Popitem – This method will remove and returns the arbitrary element.

Dic = {1: 'Python', 'name': 'dictionary'}
pop_ele = Dic.popitem()
print('\nDic after deletion: ' + str(Dic))
print('poped key is: ' + str(pop_ele))

5) Get – This is conventional method used to access value from the key.

Dic = {1: 'Python', 'name': 'dictionary'}
print (Dic.get (1))

Conclusion

The dictionary includes key-value pairs. It can be formed in Python by enclosing a succession of entries in curly braces and separating them with a comma. The dictionary stores the pair Key and the other is the Key value pair element.

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This is a guide to Python 3 Dictionary. Here we discuss the definition, Creating Python 3 Dictionary, Python 3 dictionary access, Examples with code implementation. You may also have a look at the following articles to learn more –

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