dict()

 

Dictionary

or dict() in Python

is a built-in data structure that allows us to store key-value pairs. This data structure is mutable

meaning that we can modify

add

or delete key-value pairs as needed. In this article

we will discuss the basics of dictionaries

how to use them in Python

and some common operations you can perform with dictionaries.

 

To create a dictionary in Python

you can use curly braces { } and separate each key-value pair with a colon :. For example:

 

my_dict = { "name": "John"

"age": 30

"city": "New York" }

 

In the above example

we have created a dictionary with three key-value pairs: "name" is the key and "John" is the corresponding value

"age" is the key and 30 is the corresponding value

and "city" is the key and "New York" is the corresponding value.

 

You can access the values in a dictionary by using the keys. For example

to access the value associated with the key "name" in the dictionary above

you can do:

 

print(my_dict["name"])

 

This will output "John"

as that is the value associated with the key "name" in the dictionary.

 

You can also update the value of a key in a dictionary by assigning a new value to that key. For example

to update the age in the dictionary above

you can do:

 

my_dict["age"] = 35

 

Now

the value associated with the key "age" in the dictionary will be 35 instead of 30.

 

You can also add new key-value pairs to a dictionary by simply assigning a value to a new key. For example

to add a new key "gender" with the value "male" to the dictionary above

you can do:

 

my_dict["gender"] = "male"

 

Now

the dictionary will have a new key "gender" with the value "male".

 

To delete a key-value pair from a dictionary

you can use the del keyword followed by the key. For example

to delete the key "city" and its corresponding value from the dictionary above

you can do:

 

del my_dict["city"]

 

Now

the dictionary will no longer have the key "city" and its value.

 

You can also check if a key exists in a dictionary using the in keyword. For example

to check if the key "city" exists in the dictionary above

you can do:

 

if "city" in my_dict:

print("City exists in the dictionary")

else:

print("City does not exist in the dictionary")

 

Dictionaries are a powerful data structure in Python that allows us to store and manipulate key-value pairs efficiently. They are commonly used in various programming tasks

such as database operations

configuration settings

and more. They are also widely used in web development

data analysis

and machine learning applications.

 

In conclusion

dictionaries in Python are a versatile and powerful data structure that allows us to store and manipulate key-value pairs. By understanding the basics of dictionaries and how to use them in Python

you can make your code more efficient and effective. We hope this article has been helpful in explaining the concept of dictionaries and how to work with them in Python.