What is the main difference between a dictionary and a list in Python?

Difference between List and Dictionary in Python

Lists are just like the arrays, declared in other languages. Lists need not be homogeneous always which makes it a most powerful tool in Python. A single list may contain DataTypes like Integers, Strings, as well as Objects. Lists are mutable, and hence, they can be altered even after their creation.
Example:

Python3




# Python program to demonstrate

# Lists

# Creating a List with

# the use of multiple values

List = ["Geeks", "For", "Geeks"]

print["List containing multiple values: "]

print[List[0]]

print[List[2]]

# Creating a Multi-Dimensional List

# [By Nesting a list inside a List]

List = [['Geeks', 'For'] , ['Geeks']]

print["\nMulti-Dimensional List: "]

print[List]

Output:

List containing multiple values: Geeks Geeks Multi-Dimensional List: [['Geeks', 'For'], ['Geeks']]

Dictionary in Python on the other hand is an unordered collection of data values, used to store data values like a map, which unlike other Data Types that hold only single value as an element, Dictionary holds key:value pair. Key-value is provided in the dictionary to make it more optimized. Each key-value pair in a Dictionary is separated by a colon :, whereas each key is separated by a ‘comma’.
Example:

Python3




# Python program to demonstrate

# dictionary

# Creating a Dictionary

# with Integer Keys

Dict = {1: 'Geeks', 2: 'For', 3: 'Geeks'}

print["Dictionary with the use of Integer Keys: "]

print[Dict]

# Creating a Dictionary

# with Mixed keys

Dict = {'Name': 'Geeks', 1: [1, 2, 3, 4]}

print["\nDictionary with the use of Mixed Keys: "]

print[Dict]

Output:

Dictionary with the use of Integer Keys: {1: 'Geeks', 2: 'For', 3: 'Geeks'} Dictionary with the use of Mixed Keys: {1: [1, 2, 3, 4], 'Name': 'Geeks'}



Difference between List and Dictionary:

List Dictionary
List is a collection of index values pairs as that of array in c++. Dictionary is a hashed structure of key and value pairs.
List is created by placing elements in [ ] separated by commas “, “ Dictionary is created by placing elements in { } as “key”:”value”, each key value pair is separated by commas “, “
The indices of list are integers starting from 0. The keys of dictionary can be of any data type.
The elements are accessed via indices. The elements are accessed via key-values.
The order of the elements entered are maintained. There is no guarantee for maintaining order.

Space-Time Trade-Off

It is more efficient to use a dictionary for lookup of elements because it takes less time to traverse in the dictionary than a list.
For example, let’s consider a data set with 5000000 elements in a machine learning model that relies on the speed of retrieval of data. To implement this we have to choose wisely between two data structure i.e. list and dictionary. The dictionary is preferred because of less time and less space storage as dictionaries are implemented in the form of hash tables from python3.6 so it is never a space-time trade-off problem in dictionaries.
Example 1:

Python3




# Program to demonstrate

# space-time trade-off between

# dictionary and list

# To calculate the time

# difference

import time

# Creating a dictionary

d ={'john':1, 'alex':2}

x = time.time[]

# Accessing elements

print["Accessing dictionary elements:"]

for key in d:

print[d[key], end=" "]

y = time.time[]

print["\nTime taken by dictionary:", y-x]

# Creating a List

c =[1, 2]

x = time.time[]

print["\nAccessing List elements:"]

for i in c:

print[i, end=" "]

y = time.time[]

print["\nTime taken by dictionary:", y-x]

Output:

Accessing dictionary elements: 1 2 Time taken by dictionary: 1.0013580322265625e-05 Accessing List elements: 1 2 Time taken by dictionary: 3.5762786865234375e-06

Example 2:

Python3




# Program to fetch particular

# elements of structure

import time

# Creating dictionary and list

dict_name ={"bob":12, "john":11}

list_name =[2, 3, 4, 5, 1]

# Time taken by dictionary

x = time.time[]

L = dict_name["bob"]

y = time.time[]

print["Time taken by dictionary:", y-x]

# Time taken by list

x = time.time[]

L = list_name[2]

y = time.time[]

print["\nTime taken by list:", y-x]

Output:

Time taken by dictionary: 9.5367431640625e-07 Time taken by list: 4.76837158203125e-07

Note: It took more time for fetching a single element in a list than that of a dictionary because dictionary uses hashtable for implementing the arrangement.




Article Tags :

Python

python-dict

python-list

Practice Tags :

python-dict

python-list

Read Full Article

List vs Dictionary | 10 Difference Between List and Dictionary

Python supports various in-built data structures to make the programming easy and efficient like any other programming language. All these python data structures are sequential and store data collection in various formats, unlike others. List and dictionary are some of those python data structures that are simple yet powerful and store a wide range of data. This article will explain list and dictionary data structure and their difference and when to use list vs. dictionary in Python.

Difference between list and dictionary

List and dictionary are fundamentally different data structures . A list can store a sequence of objects in a certain order such that you can index into the list, or iterate over the list. Moreover, List is a mutable type meaning that lists can be modified after they have been created. Python dictionary is an implementation of a hash table and is a key-value store. It is not ordered and it requires that the keys are hashtable. Also, it is fast for lookups by key.

Elements in a list have the following characteristics:

  1. They maintain their ordering unless explicitly re-ordered [for example, by sorting the list].
  2. They can be of any type, and types can be mixed.
  3. They are accessed via numeric [zero based] indices.

Elements in a Dictionary have the following characteristics:

  1. Every entry has a key and a value
  2. Ordering is not guaranteed
  3. Elements are accessed using key values
  4. Key values can be of any hashtable type [i.e. not a dict] and types can be mixed
  5. Values can be of any type [including other dict’s], and types can be mixed
Usage:

Use a dictionary when you have a set of unique keys that map to values and to use a list if you have an ordered collection of items.


Next:Different file processing modes supported by Python





  • Python Interview Questions [Part 2]
  • Python Interview Questions [Part 3]
  • What is python used for?
  • Is Python interpreted, or compiled, or both?
  • Explain how python is interpreted
  • How do I install pip on Windows?
  • How do you protect Python source code?
  • What are the disadvantages of the Python?
  • How would you achieve web scraping in Python?
  • How to Python Script executable on Unix
  • What is the difference between .py and .pyc files?
  • What is __init__.py used for in Python?
  • What does __name__=='__main__' in Python mean?
  • What is docstring in Python?
  • What is the difference between runtime and compile time?
  • How to use *args and **kwargs in Python
  • Purpose of "/" and "//" operator in python?
  • What is the purpose pass statement in python?
  • Why isn't there a switch or case statement in Python?
  • How does the ternary operator work in Python?
  • What is the purpose of "self" in Python
  • How do you debug a program in Python?
  • What are literals in python?
  • What is Python's parameter passing mechanism?
  • What is the process of compilation and Loading in python?
  • Global and Local Variables in Python
  • Is there a tool to help find bugs or perform static analysis?
  • What does the 'yield' keyword do in Python?
  • Comparison Operators != is not equal to in Python
  • What is the difference between 'is' and '==' in python
  • What is the difference between = and == in Python?
  • How are the functions help[] and dir[] different?
  • What is the python keyword "with" used for?
  • Is all the memory freed when Python exits?
  • Difference between Mutable and Immutable in Python
  • Explain split[] methods of "re" module in Python
  • Accessor and Mutator methods in Python
  • How to Implement an 'enum' in Python
  • Important characteristics of Python Objects
  • How to determine the type of instance and inheritance in Python
  • How would you implement inheritance in Python?
  • How is Inheritance and Overriding methods are related?
  • How can you create a copy of an object in Python?
  • How to avoid having class data shared among instances in Python?
  • Static class variables in Python
  • Difference between @staticmethod and @classmethod in Python
  • How to Get a List of Class Attributes in Python
  • Does Python supports interfaces like in Java or C#?
  • What is used to create Unicode string in Python?
  • Difference between lists and tuples in Python?
  • Different file processing modes supported by Python
  • How do you append to a file in Python?
  • What are the differences between the threading and multiprocessing?
  • Is there any way to kill a Thread in Python?
  • What is the use of lambda in Python?
  • What is map, filter and reduce in python?
  • Is monkey patching considered good programming practice?
  • What is "typeerror: 'module' object is not callable"
  • Python: TypeError: unhashable type: 'list'
  • How to convert bytes to string in Python?
  • What are metaclasses in Python?





List Vs. Dictionary in Python: Know the Difference Between List and Dictionary in Python

Both of these are tools used in the Python language, but there is a crucial difference between List and Dictionary in Python. A list refers to a collection of various index value pairs like that in the case of an array in C++. A dictionary refers to a hashed structure of various pairs of keys and values. In this article, we will discuss the same in a tabular form. But let us first know a bit more about each of these individually.

“what is the difference between list and dictionary in python” Code Answer’s


difference between two dictionaries python

python by Talented Trout on Sep 24 2021 Comment

0

Source: stackoverflow.com

difference between dictionary and sets in python

typescript by PassionateCoder7 on Feb 10 2021 Comment

1

Add a Grepper Answer


Python answers related to “what is the difference between list and dictionary in python”

  • dict from two lists
  • dictionary from two lists
  • 2 list difference python
  • difference between list vs set vs map in java
  • python list of dictionaries to list
  • compare two dictionaries in python
  • Python difference between filter and map
  • difference between set and list in python
  • find different between list
  • 2 liste to a dictionary
  • dictionary from two list
  • how to compare values in dictionary with same key python

Python queries related to “what is the difference between list and dictionary in python”

  • difference between set and dictionary in python
  • compare two dictionaries python
  • what is the difference between set and dictionary in python
  • dict difference site:python.org
  • how to compare two dictionaries in python
  • comparing two dictionaries in python
  • difference between dictionary and list
  • difference between array and dictionary
  • difference between dict and dict python
  • difference between list and dictionaries in python
  • how to find difference between two dictionaries python
  • python difference between set and dictionary
  • python difference between two dictionaries
  • difference between dict and {} python
  • find difference between dictionaries python
  • python difference between dictionary and object
  • python print difference between two dictionaries
  • between dictionary python
  • difference between object and dictionary
  • get difference between two values in dictionary python
  • difference dict and set python
  • difference set and dict
  • what is the difference between a dictionary and a set in python?
  • what is the difference between dictionary and set in python
  • difference between dictionary , list, tuple,set in python
  • difference between set and dictionary in pytholn
  • difference between set and dictionaries in python
  • difference between set and dict in python
  • diff between set and dictionary
  • difference between lists, dictionaries and sets in python
  • difference between an object and dict
  • python compare two nested dictionaries
  • difference between list and dictionary and array
  • difference between dictionary and json in python
  • dictionary and map difference
  • difference between 2 dicts
  • difference between python array and dictionary
  • 2 dict difference between
  • can we compare 2 dictionaries in python
  • compare two dictionaries with nested in python and return the difference
  • diff two dictionaries python
  • python difference dict point dict []
  • python 3.8 get differences between two dictionaries
  • what is the difference between lists and dictionaries
  • get diff between two dicts python
  • python compare 2 dictionaries
  • compare 2 dictionaries python
  • python difference between numbers in dictionaries
  • write the difference between list and dictionary in python.
  • python object dict difference
  • how to compare two dictionaries and return the difference
  • difference between set tuple dictionary and list in python
  • difference between list tuple dictionary and set in python
  • difference between dictionary and set in python
  • python compare two dictionaries
  • array vs dictionary python
  • sets vs dictionaries python
  • what the difference between list and dictionaries in python
  • python difference beween dictioraz and object
  • difference between array and dictionary in python
  • how to check differences between in dictionarty in python
  • dict.difference python
  • difference between dictionary and object
  • python compare two dicts
  • python difference between dictionaries
  • difference between dict values and items
  • difference between map and dictionary
  • find difference in two dictionaries python
  • difference in dicitonary pytho
  • python dict diff between dictionaries
  • difference between list and dictionary
  • python set dictionary difference
  • python set of dictionaries difference
  • sets vs dictioary in python
  • wahts the difference between dictionarty adn set in python
  • major differences between set and dictionary in python
  • difference between dict and set
  • compare dict python
  • . state the difference between set and dictionaries in python
  • what is the difference between "dict" and "orderdict"
  • difference between key and dictionary in python
  • wo differences between a set and a dict
  • difference between two dictionary python
  • how to compare 2 dictionaries in python
  • python dict difference
  • python get difference between two nested dictionaries
  • how to compare two different dictionaries in python
  • difference between dictionary and dictionary.items[]
  • python array vs dictionary
  • find similarities between two dicts python
  • heck the difference between two dictionaries and print
  • compare two dictionaries in python and return the difference
  • list and dictionary difference in python
  • python what is the difference between dict.keys[], and list[dict.keys[]
  • python get differences between two dictionaries
  • difference between values of dict with same key python
  • python diff two dictionaries
  • difference between two dicts lists python
  • return difference between two dictionaries python
  • python difference between hash map and dictionary
  • differences between dictionaries python
  • difference between modulo and dictionary in python
  • python difference between dict and defaultdict
  • python get difference between two dictionaries
  • what is difference between set and dictionary in python
  • what is the difference between list and dictionary in python
  • difference between sets and dictionaries in python
  • difference between 2 dictionaries python
  • whats the difference between a dictionary and a list python
  • python difference between dict and dict
  • compare two dictionaries in python
  • difference between dictionary and sets in python
  • difference between dict and set in python
  • difference between dictionary and list in python
  • python dictionary difference
  • difference between list and dictionary in python
  • what is the difference between list and dictionary in python?
  • difference between two dictionaries
  • python difference between dictionary and set
  • difference between between object dict and class dict
  • python dictionary difference values
  • find differences between twoi dicts
  • python difference between dict and {}
  • difference between a set and a dictionary in python
  • sets vs dictionaries python
  • difference between set and dictionary
  • keys vs values python dict
  • difference between key and value in dictionary python
  • how python differnice betwen dict and set
  • differenece between set and dictionary in python
  • diff two dicts in python
  • differece between dictionaries python
  • difference between dictionaries in python
  • python difference between attribute dict point dict []
  • difference between dictionary and list python
  • difference between dict in python
  • difference between a dictionary and a collocations
  • difference python dictionary and json
  • find difference between two dictionaries python
  • compare 2 dictionaries python 3
  • comparing two dictionaries in python using ==
  • python compare two dictionaries with same keys and values
  • dictionary difference python
  • find difference between two dicts python
  • python find the difference between two dictionaries
  • what is difference between list and dictionaries in python
  • difference between two dicts python
  • difference between idictionary and dictionary
  • difference dictionary python
  • difference between map and dict in python
  • write the difference between list and dictionary in python
  • list and dictionary in python difference
  • how to return differences in values in two dictionaries in python
  • difference between dict and dict.string

Video liên quan

Bài mới nhất

Chủ Đề