What are different ways of creating dictionaries?

The different ways of creating dictionaries in Python are:

1. By using curly brackets and separating key-value pairs with commas as per the syntax below:

<dictionary-name> = {<key>:<value>, <key>:<value>...} 

For example:

d = {'a': 1, 'b': 2, 'c': 3} 

2. By using dictionary constructor dict(). There are multiple ways to provide keys and values to dict() constructor:

i. Specifying key:value pairs as keyword arguments to dict() function:
For example:

Employee = dict(name = 'john' , salary = 1000, age = 24)
print(Employee)

Output

{'name': 'john', 'salary': 1000, 'age': 24}  

ii. Specifying comma separated key:value pairs:
Key:value pairs are enclosed in curly braces in this format.
For example:

Employee = dict({'name': 'john', 'salary': 1000, 'age': 24})

Output

{'name': 'john', 'salary': 1000, 'age': 24} 

iii. Specifying keys and its corresponding values separately:
Keys and Values are enclosed separately in parentheses and are given as arguments to zip() function.
For example:

Employee = dict(zip(('name','salary','age'),('John',10000,24))) 

Output

{'name': 'John', 'salary': 10000, 'age': 24} 

iv. Specifying key:value pairs separately in form of sequences:
One list or tuple that contains lists/tuples of individual key:value pairs is passed as an argument to dict().
For example:

Employee = dict([['name','John'],['salary',10000],['age',24]]) 
print(Employee)

Output

{'name': 'John', 'salary': 10000, 'age': 24} 

3. By using fromkeys() function:
fromkeys() function is used to create a new dictionary from a sequence containing all the keys and a common value, which will be assigned to all the keys.
For example:

x = ('list', 'set', 'dictionary')
y = 'mutable'
my_dict = dict.fromkeys(x, y)
print(my_dict)

Output

{'list': 'mutable', 'set': 'mutable', 'dictionary': 'mutable'}