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Table of contents
1.
Introduction
2.
Python dictionary
3.
When should I use a Python dictionary? 
4.
Python Dictionary fromkeys Definition
5.
Method declaration
6.
Parameter Arguments:
7.
Return value
8.
Example 1
8.1.
Output
8.2.
Explanation,
9.
Example 2
9.1.
Output
9.2.
Explanation
10.
Frequently Asked Questions
10.1.
How do I change a list in Python into a dictionary?
10.2.
What is an example of a Python dictionary? 
10.3.
Why does Python utilize Fromkeys?
10.4.
What's the process for Dict from Python Dictionary fromkeys?
10.5.
What is an example of a Python dictionary?
11.
Conclusion
Last Updated: Mar 27, 2024
Easy

FromKeys() method in Python Dictionaries

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Introduction

Hello Ninja! Welcome back to another chapter of our Python lesson. This instructional manual will discuss the Python Dictionary fromkeys() technique.  

Introduction

The Python Dictionary fromkeys() method generates a new dictionary with keys from seq and values set to value.

Python dictionary

data structure for working with key/value pair-stored data sets is the Python dictionary. As with Python 3.7, dictionaries are sorted and changeable. One of example is Python Dictionary fromkeys. Dictionaries may accommodate modifications made after an entry has been created, although they are stringent about duplicate entries. Every key/value combination needs to be distinct. Now we understand Python Dictionary fromkeys.

Python dictionary

Once you've made a dictionary, you can use the key for each value to go to the objects within.

Check out this article, Fibonacci Series in Python

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When should I use a Python dictionary? 

  • When the value of the data may be linked to a specific reference. 
     
  • When having rapid access to data is crucial. Dictionaries are made to make it possible for us to quickly discover a value without having to search through the entire collection. 
     
  • When the order of the data is not significant. 
     
  • It is not a good idea to use dictionaries to store data that shouldn't be changed in the first place since they are changeable. 
     
  • When the program does not prioritize memory consideration. The memory requirements of dictionaries are higher than those of lists and tuples.

Python Dictionary fromkeys Definition

So, finally, we will get to know about Python Dictionary fromkeys. A dictionary containing the supplied keys either to optionally specified values or to the default. The function dict produces none value.fromkeys(), which accepts keys and perhaps an optional value as inputs. The method declaration of Python Dictionary fromkeys is shown below.

Method declaration

dict.fromKeys(keys, optional_value)

Parameter Arguments:

Keys Required input Iterable input that specifies the dictionary shouldn't new keys
optional_value Optional input Every key in the dictionary has a specified value allocated to it; None is used by default as the optional value.

Return value

This function returns a newly formed dictionary with the supplied keys and values, and its return type is of the <class 'dictionary DICT'>.

Now we move into the examples of Python Dictionary fromkeys

Example 1

# Python code function for Python Dictionary fromkeys 
 
s = ("CodingNinja", "Tutorial", "Website")
t = 1
x = dict.fromkeys(s, t)
print(x)

Output

{'CodingNinja': 1, 'Tutorial': 1, 'Website': 1}

Explanation,

In this case, it provided a dictionary that had the given keys together with a fixed value for each of them. None is returned as the entire value if no parameter is passed. This is how we use Python Dictionary fromkeys.

Example 2

# Python code function for Python Dictionary fromkeys 
 
s = ("CodingNinja", "python", "TUTORIAL")

x = dict.fromkeys(s)
print(x)

Output

{'CodingNinja': None, 'python': None, 'TUTORIAL': None}

 

You can compile it with online python compiler.

Explanation

Since no value was given in the code. It here produced a dictionary with keys and none as their values. This is how we use Python Dictionary fromkeys.

Frequently Asked Questions

How do I change a list in Python into a dictionary?

The output can be in any sequence because the Python dictionary is unordered. Using list comprehension, we may create a key: value pair of consecutive entries from a list to create a dictionary. The list should then be typecasted to dict type.

What is an example of a Python dictionary? 

A collection of things in a Python dictionary is not sorted. Each item in a dictionary contains a key/value pair. When the key is known, dictionaries are designed to retrieve values quickly.

Why does Python utilize Fromkeys?

The fromkeys() method of a dictionary in Python returns a dictionary with mapped keys and particular values. From the supplied sequence, it creates a new dictionary with the desired value.

What's the process for Dict from Python Dictionary fromkeys?

A new dictionary is made using the specified sequence of items and a value entered by the user using the built-in Python method dict. fromKeys(). The dictionary with the requested keys and values is returned by the fromKeys method.

What is an example of a Python dictionary?

A collection of things in a Python dictionary is not sorted. A dictionary has a key/value pair for each entry. When the key is known, dictionaries are designed to retrieve values quickly.

Conclusion

In this blog, we have learned about Python Dictionary fromkeys. This is the point at which we will wrap up this tutorial article. Please feel free to ask any questions you may have, and I will do my best to answer them. Use the link to spread the word about this tutorial if you found it useful.

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Also check out - Data Dictionary In Software Engineering

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