Creating lists in python - The append function will add the item at the end of the list. The function lets you insert data in the place you want on the list. It'll take two parameters, the index, and the value. Let's see an example: items = ["mobile", "laptop", "headset"] # append the keyboard item to the list. items.append("keyboard")

 
Apr 4, 2015 · Depends, if you are using Python 2.X it does but for Python 3.X it produces a range object which should be iterated upon to create a list if you need to. But in any case for all practical purpose extending a range object as a List comprehension is useless and have an unnecessary memory hogging. . Software keep

Sep 3, 2023 · To create a nested list in Python, you enclose one or more lists within square brackets, like this: nested_list = [[8, 9, 10], ['x', 'y', 'z'], [True, False]] This code defines a variable named nested_list, which is a Python list containing three inner lists. Each inner list in this example, holds different types of data, such as numbers ...Apr 30, 2023 · Creating a list of lists in python is a little tricky. In this article, we will discuss 4 different ways to create and initialize list of lists. Wrong way to create & initialize a list of lists in python. Let’s start from basic, quickest way to create and initialize a normal list with same values in python is, In Python, nested lists are lists that contain other lists as their elements. They can be useful for storing and manipulating complex data structures, such as matrices, graphs, or trees. ... from pprint import pprint # Creating a 3x3x3 nested list of zeros using list comprehension nested_list = [[[0 for i in range(3)] for j in range(3)] for k ...Jul 20, 2020 · Technique 1: Using square brackets. We can use square brackets to create an empty list in Python. As we all know, a List uses square brackets to store its elements into it. Thus, it can be applied here as well. Jul 6, 2022 · Here are some of the features of a list in Python: Items in a list can have duplicates. This means that you can add two or more items with the same name. Items in a list are ordered. They remain in the same order as you create and add items to a list. Items in a list are changeable. This means that you can modify the value of an item in a list ... Jan 8, 2017 ... To create a List, the elements are placed inside Square Brackets ''[ ]”, separated by Commas “,”.In the world of e-commerce, having a wish list feature on your website can greatly enhance the shopping experience for your customers. A wish list allows users to save items they a...Choosing the right name for your business is a crucial step in building a successful brand. A well-thought-out business name can help you stand out from the competition, attract cu...In Python, there’s a specific object in the collections module that you can use for linked lists called deque (pronounced “deck”), which stands for double-ended queue. collections.deque uses an implementation of a linked list in which you can access, insert, or remove elements from the beginning or end of a list with constant O (1 ...Feb 16, 2023 · You can create a list in Python by separating the elements with commas and using square brackets []. Let's create an example list: myList = [3.5, 10, "code", [ 1, 2, 3], 8] From the example above, you can see that a list can contain several datatypes. In order to access these elements within a string, we use indexing. Jul 6, 2022 · Learn how to create, add, access, change, and remove items in a list in Python with examples and syntax. A list is a data structure that can store different data types, have …Jan 7, 2020 ... You can create list using the following syntax. ... Other ways of creating list. ... note: Lists are mutable. Accessing elements in list #. You can ...Jan 7, 2020 ... You can create list using the following syntax. ... Other ways of creating list. ... note: Lists are mutable. Accessing elements in list #. You can ... Discussion. 00:00 One way to create lists in Python is using loops, and the most common type of loop is the for loop. You can use a for loop to create a list of elements in three steps. 00:10 Step 1 is instantiate an empty list, step 2 is loop over an iterable or range of elements, and step 3 is to append each element to the end of the list. Take the Quiz » Python Lists. In short, a list is a collection of arbitrary objects, somewhat akin to an array in many other programming languages but more flexible. Lists are defined in Python by enclosing a comma-separated …Mar 1, 2024 · In Python, lists are a cornerstones of data organization and manipulation – so I think they deserve a thorough exploration. This article delves into how to create and manipulate lists in Python, some advanced functionalities, and some practical applications of lists. You can get all the source code from Oct 22, 2021 · languages = ['Python', 'Go', 'Dart'] if 'Python' in languages: print('I <3 Python') Creating and initializing new lists. We’ve initialized the previous list with pre-defined values. There are some other ways to initialize lists, too. Over 200k developers use LogRocket to create better digital experiences.4 days ago · Creating Lists. A list is created by placing items inside [], separated by commas . For example, # A list with 3 items numbers = [1, 2, -5] # List containing duplicate values numbers = …Feb 2, 2024 · Python Python List. Use the append () Function to Create a List of Lists in Python. Use the List Comprehension Method to Create a List of Lists in Python. Use the for Loop to Create a List of Lists in Python. We can have a list of many types in Python, like strings, numbers, and more. Python also allows us to have a list within a list called a ... May 1, 2020 · I've been trying to practice with classes in Python, and I've found some areas that have confused me. The main area is in the way that lists work, particularly in relation to inheritance. Here is my Code. def __init__(self, book_id, name): self.item_id = book_id. self.name = name. Creating list from list in python based on an if condition. 0. Making one list that satisfies the condition. 5. Python array elements in if statement. 0. If condition in Python and create list. 2. Conditionally create list of lists. 1. Creating lists based on conditional value. Hot Network QuestionsThere are four collection data types in the Python programming language: 1. Listis a collection which is ordered and changeable. Allows duplicate members. 2. Tupleis a collection which is ordered and unchangeable. Allows duplicate members. 3. Setis a collection which is unordered, … See morePython is a versatile programming language that is widely used for game development. One of the most popular games created using Python is the classic Snake Game. To achieve optima...In your example, x is a list containing three elements (integers). With append, you add a new element. By appending y, you are adding a list as a fourth element (3 integers, one list). If you want to create a list of lists, tread x and y as elements for that, and combine them in a list: x = [1,2,3] y = [4,5,6] list_of_lists = [x,y] @Reman It's not entirely clear what you want to get but if it is, for example, also the reverse of each tuple you can use a a wrapper function that takes a as input, iterates over itertools.product(*a) and yields both the tuple produced by itertools and a reverse version (e.g. create a list, reverse() it and convert back to tuple). Best ask a ... This, as the name implies, provides ways to generate combinations of lists. Now that you know how the combinations () function works, let’s see how we can generate all possible combinations of a Python list’s items: for n in range ( len (sample_list) + 1 ): list_combinations += list (combinations(sample_list, n))Feb 8, 2024 · The below code initializes an empty list called listOfList and, using a nested for loop with the append () method generates a list of lists. Each inner list corresponds to a row, and the elements in each row are integers from 0 to the row number. The final result is displayed by printing each inner list within listOfList. Python. listOfList = [] Sep 30, 2021 · In this post, you learned different ways of creating a Pandas dataframe from lists, including working with a single list, multiple lists with the zip () function, multi-dimensional lists of lists, and how to apply column names and datatypes to your dataframe. To learn more about the Pandas dataframe object, check out the official documentation ...Neptyne, a startup building a Python-powered spreadsheet platform, has raised $2 million in a pre-seed venture round. Douwe Osinga and Jack Amadeo were working together at Sidewalk...Feb 2, 2024 · Python also allows us to have a list within a list called a nested list or a two-dimensional list. In this tutorial, we will learn how to create such lists. Use the append() Function to Create a List of Lists in Python. We can add different lists to a common list using the append() function. It adds the list as an element to the end of the list.May 1, 2023 · Time Complexity: O(N) Auxiliary Space: O(N) Method 4: Use the built-in zip function along with a list comprehension. Step-by-step approach: Initialize two lists: one with the keys (test_list) and another with the corresponding values (each value being the concatenation of “def_key_” and the corresponding key). Adding Elements to the List. There are numerous possible ways in which we can add the elements to this list, Moreover, python has an innate function, we call it append (). Further, while using the append () function, we can only add a single element to this list. Moreover, if we want to add numerous elements to this list then we must have to ...May 6, 2023 · Create list of floats in Python. Let us see, how to create a list of floats in Python. A list of floats is a list containing floating-point numbers. To create a list of floats, follow the same steps as for creating a list, but use floating-point numbers as items. Step 1: Initialize an empty list of floats. city_populations = [] Lists in python are declared using square brackets. What goes inside these brackets is a comma separated list of items. If no items are provided, an empty list is created. Similar to creating variables of other types, python first allocates some memory for the list object and assigns the variable L to refer to it.Oct 21, 2022 ... The Problem You want to flatten both regular and irregular lists of lists. Nested for loops could be used to solve this problem.Feb 25, 2022 · Run the code, and you’ll get the value of toaster from the ‘products’ list, as well as the value of 120 from the ‘prices’ list (those are indeed the third values in those lists):. toaster 120 You can also access a range of values in your lists. For instance, let’s say that you want to print the last 3 products in the ‘products’ list.If we compare the runtimes, among random list generators, random.choices is the fastest no matter the size of the list to be created. However, for larger lists/arrays, numpy options are much faster. So for example, if you're creating a random list/array to assign to a pandas DataFrame column, then using np.random.randint is the fastest option.Neptyne, a startup building a Python-powered spreadsheet platform, has raised $2 million in a pre-seed venture round. Douwe Osinga and Jack Amadeo were working together at Sidewalk...A list: a = ['a', 'b', 'c', 3, 4, 'd', 6, 7, 8] I want a list using a subset of a using a[0:2],a[4], a[6:], that is I want a list ['a', 'b', 4, 6, 7, 8] ... creating a new list with subset of list using index in python. Ask Question Asked 10 years, ... I used the %timeit functionality of Jupyter Notebook / iPython on a Windows 10 system with ...You can make a shorter list in Python by writing the list elements separated by a comma between square brackets. Running the code squares = [1, 4, 9, 16, ...Dec 7, 2021 · Creating Python Lists. Let’s now take a look at how we can create Python lists. To create an empty list, you have two different options: Using the list () function. Using empty square brackets, [] Let’s take a look at what this looks …Mar 18, 2019 · Lists in Python. Lists in Python. Creating lists. Simple ways to create a list. Hard code the values mylist = [3, 9, ‘a’, 7.2] Using the replication operator mylist = [0] * 100 (gives a list with 100 zeros ) Use the split method on a string Use the readlines method on a file.Creating lists in Python. A list in Python can contain any number of elements. You generally create a list using square brackets. For example, to create a list of integers, you can use the following command: x = [1, 2, 3]The toList method in Numpy will convert directly to a python list of lists while keeping the order of the inner lists intact. No need to create a new empty list and load it up with all the individual items. The toList method does all the heavy lifting for you. import numpy as np. npArray = np.array([. In python, as far as I know, there are at least 3 to 4 ways to create and initialize lists of a given size: Simple loop with append:. my_list = [] for i in range(50): my_list.append(0) In your example, x is a list containing three elements (integers). With append, you add a new element. By appending y, you are adding a list as a fourth element (3 integers, one list). If you want to create a list of lists, tread x and y as elements for that, and combine them in a list: x = [1,2,3] y = [4,5,6] list_of_lists = [x,y]List concatenation in Python is quite simple, all we need to do is add them with the addition sign. Adding nested lists works the same way as adding plain, unnested lists. In our example, we’ll add the two lists we created using list comprehension together. # concat nested lists. concat_nlist = nlist_comp1 + nlist_comp2.Sep 5, 2023 · Python's *for* and *in* constructs are extremely useful, and the first use of them we'll see is with lists. The *for* construct -- for var in list -- is an easy way to look at each element in a list (or other collection). Do not add or remove from the list during iteration. squares = [1, 4, 9, 16] sum = 0. for num in squares: The list initializer syntax is used to create a list in Python. We can use this technique to create a list of lists by passing lists as elements into the list initializer. See the code and output. # Take two lists. list1 = [1,2,3,4] list2 = …Mar 8, 2024 · In this example, we have a list my_list with five elements. We want to remove the element with index 2, which has the value 3. We use the del statement and specify the index of the item we want to remove. After removing the element, we print the updated list.In today’s digital age, targeted marketing has become essential for businesses looking to reach their ideal customers. One effective way to achieve this is by creating a mailing li...Python's *for* and *in* constructs are extremely useful, and the first use of them we'll see is with lists. The *for* construct -- for var in list -- is an easy way to look at each element in a list (or other collection). Do not add or remove from the list during iteration. squares = [1, 4, 9, 16] sum = 0. for num in squares:Dec 27, 2023 · Python List comprehension provides a much more short syntax for creating a new list based on the values of an existing list. List Comprehension in Python Example. Here is an example of using list comprehension to find the square of the number in Python. Mar 29, 2022 · Creating a list. To create a list we can use two main methods: Using [] to enclose what we want to contain in the list with items separated by commas. Using the list () function which can be used to convert other data structures to lists or takes a list as an argument. These can be simply implemented as:The program should have a menu at the start telling what the person can do to add, print and replace people in the list. So the program should have a loop, and do things according to user input. To get user input use. answer = input("") Here is pseudocode of how this should look like: workers = [] def main(): while True:Mar 1, 2024 · In this approach we use the * operator with a list containing the default value to create a list with the specified size, where each element is a reference to the same object. Python3. size = 5. placeholder_value = 0. my_list = [placeholder_value] * size. print(my_list) Output. [0, 0, 0, 0, 0] Python doesn't have a built-in type for matrices. However, we can treat a list of a list as a matrix. For example: A = [[1, 4, 5], [-5, 8, 9]] We can treat this list of a list as a matrix having 2 rows and 3 columns. Be sure to learn about Python lists before proceed this article.Do you find yourself spending too much time manually entering data into your Excel spreadsheets? Are you tired of dealing with typos and inconsistencies? Creating a dynamic drop-do...Feb 2, 2024 · Python Python List. Use the append () Function to Create a List of Lists in Python. Use the List Comprehension Method to Create a List of Lists in Python. Use the for Loop to Create a List of Lists in Python. We can have a list of many types in Python, like strings, numbers, and more. Python also allows us to have a list within a list called a ... Is there a built in list in python or some package that has a list of the alphabet?-5. How can I create a list from a to z, and A to Z. 11. Is it possible to make a letter range in python? 9. How to get the current locale's alphabet in Python 3? 2. Count how many times each letter appears in a text sample-1.Every time you call .append() on an existing list, the method adds a new item to the end, or right side, of the list. The following diagram illustrates the process: Python lists reserve extra space for new items at the end of the list. A call to .append() will place new items in the available space.. In practice, you can use .append() to add any kind of object to a given list:There are four collection data types in the Python programming language: 1. Listis a collection which is ordered and changeable. Allows duplicate members. 2. Tupleis a collection which is ordered and unchangeable. Allows duplicate members. 3. Setis a collection which is unordered, … See moreMar 1, 2024 · In this approach we use the * operator with a list containing the default value to create a list with the specified size, where each element is a reference to the same object. Python3. size = 5. placeholder_value = 0. my_list = [placeholder_value] * size. print(my_list) Output. [0, 0, 0, 0, 0] Jan 8, 2017 ... To create a List, the elements are placed inside Square Brackets ''[ ]”, separated by Commas “,”.Apr 10, 2023 ... Lists are mutable, meaning you can change their content by adding, removing, or modifying elements. Creating a list in Python is straightforward ...Nov 21, 2023 · Method 1: Python create matrix using lists. Creating a matrix using a list in Python is straightforward. We can create a matrix as a list of lists, where each inner list represents a row in the matrix. Example: …Apr 18, 2023 · Python | Initializing multiple lists. In real applications, we often have to work with multiple lists, and initialize them with empty lists hampers the readability of code. Hence a one-liner is required to perform this task in short so as to give a clear idea of the type and number of lists declared to be used. Method #1: Using loops.Dec 6, 2023 · Python is a great language for data analysis, primarily because of the fantastic ecosystem of data-centric Python packages. Pandas is one of those packages, making importing and analyzing data much easier. Creating a Pandas Dataframe can be achieved in multiple ways. Let’s see how we can create a Pandas DataFrame from Lists.Aug 18, 2022 · Sometimes, in making programs for gaming or gambling, we come across the task of creating a list all with random numbers in Python. This task is to perform in general using loop and appending the random numbers one by one. ... Python Random module is an in-built module of Python which is used to generate random numbers. This module can be used ...What I want is to add the incremental value to the step to become the new step value p.e. step = 1+1 =2, new step =2, new step = 3, new step = 4 etc. Yes increment the step by one on each iteration. Either use a while loop, or a generator (generators can store state of step, whereas iterators can't) as per the top-two answers here.Dec 7, 2023 · In Python, data structures like lists are fundamental. Understanding how to input and manage them properly is crucial for effective programming. The Python input() function is versatile and can be used for various purposes, including creating a list. Using a combination of input() and list comprehension, you can dynamically design a list containing user-supplied values.Aug 9, 2023 · [{1: 'Geeks', 2: 'GeeksforGeeks'}, {1: 'Python', 2: 'Programming'}] Update a Dictionary to Python List of Dictionary. We can also update a value of a Python dictionary in the list of dictionaries. Example: In this example, we will update the existing list of dictionaries in various ways. First, we update a dictionary of the list by adding a new ...May 1, 2023 · Time Complexity: O(N) Auxiliary Space: O(N) Method 4: Use the built-in zip function along with a list comprehension. Step-by-step approach: Initialize two lists: one with the keys (test_list) and another with the corresponding values (each value being the concatenation of “def_key_” and the corresponding key). Mar 8, 2024 · In this example, we have a list my_list with five elements. We want to remove the element with index 2, which has the value 3. We use the del statement and specify the index of the item we want to remove. After removing the element, we print the updated list.May 5, 2023 · Lists are just like arrays, declared in other languages. Lists need not be homogeneous always which makes it the most powerful tool in Python. A single list may contain data types like Integers, Strings, as well as Objects. Lists are mutable, and hence, they can be altered even after their creation.Dec 15, 2021 · After taking the space separated values as input, we will use the python string split operation to get a list of all the input values. This can be observed in the following example. input_values = input ("Enter the values in the list separated by space:\n") input_list = input_values.split () print ("The list given as input by the user is ...Mar 15, 2024 · Codeacademy’s free course, Python 2, and The Hitchhiker’s Guide to Python are free resources to learn. Beginner projects include creating secure password generators and …Nov 23, 2023 · Creating an empty list in Python is easy and it’s done just like this: my_list = [] Once you have an empty list, you can add items to the list using various methods. For example, if you want to append a new item to the end of your list: my_list.append(item) If you know how many elements you’re going to need in advance, you can initialize ...Aug 31, 2021 · Covert Two Lists into a Dictionary with Python Zip. The Python zip() function is an incredibly helpful function to make iterating or multiple iterators much easier.To learn about the zip() function a bit more, check out my in-depth tutorial on zipping multiple Python lists.. Let’s see how we can use the zip() function to convert two Python lists into a dictionary:Creating list from list in python based on an if condition. 0. Making one list that satisfies the condition. 5. Python array elements in if statement. 0. If condition in Python and create list. 2. Conditionally create list of lists. 1. Creating lists based on conditional value. Hot Network QuestionsIn your example, x is a list containing three elements (integers). With append, you add a new element. By appending y, you are adding a list as a fourth element (3 integers, one list). If you want to create a list of lists, tread x and y as elements for that, and combine them in a list: x = [1,2,3] y = [4,5,6] list_of_lists = [x,y]Mar 1, 2024 · In this approach we use the * operator with a list containing the default value to create a list with the specified size, where each element is a reference to the same object. Python3. size = 5. placeholder_value = 0. my_list = [placeholder_value] * size. print(my_list) Output. [0, 0, 0, 0, 0] 3 days ago · List comprehensions provide a concise way to create lists. Common applications are to make new lists where each element is the result of some operations applied to each member of another sequence or iterable, or to create a subsequence of those elements that satisfy a certain condition. For example, assume we want to create a list of squares, like: Nov 21, 2023 · Complexities for Removing elements in the Arrays. Time Complexity: O(1)/O(n) ( O(1) – for removing elements at the end of the array, O(n) – for removing elements at the beginning of the array and to the full array Auxiliary Space: O(1) Slicing of an Array. In Python array, there are multiple ways to print the whole array with all the …The syntax for the “not equal” operator is != in the Python programming language. This operator is most often used in the test condition of an “if” or “while” statement. The test c...Apr 9, 2021 ... Creating a Python list. The list can be created using either the list constructor or using square brackets [] . Using list() constructor: In ...To perform the intersection of two lists in Python, we just have to create an output list that should contain elements that are present in both the input lists. For instance, if we have list1= [1,2,3,4,5,6] and …

Feb 22, 2022 · In this article we will talk about two such modules that can be used to create tables. Method 1: Using Tabulate module. The tabulate () method is a method present in the tabulate module which creates a text-based table output inside the python program using any given inputs. It can be installed using the below command. pip install tabulate.. Sucurly pass

creating lists in python

The trotter package is different from most implementations in that it generates pseudo lists that don't actually contain permutations but rather describe mappings between permutations and respective positions in an ordering, making it possible to work with very large 'lists' of permutations, as shown in this demo which performs pretty ... The append function will add the item at the end of the list. The function lets you insert data in the place you want on the list. It'll take two parameters, the index, and the value. Let's see an example: items = ["mobile", "laptop", "headset"] # append the keyboard item to the list. items.append("keyboard") Oct 21, 2022 ... The Problem You want to flatten both regular and irregular lists of lists. Nested for loops could be used to solve this problem.List type is another sequence type defined by the list class of python. List allows you add, delete or process elements in very simple ways. List is …Aug 9, 2023 · [{1: 'Geeks', 2: 'GeeksforGeeks'}, {1: 'Python', 2: 'Programming'}] Update a Dictionary to Python List of Dictionary. We can also update a value of a Python dictionary in the list of dictionaries. Example: In this example, we will update the existing list of dictionaries in various ways. First, we update a dictionary of the list by adding a new ...Apr 18, 2021 · Introduction to Lists. In Python, a list is an ordered sequence of elements. Unlike arrays in other languages, Python lists are dynamic in size. This means you don’t need to specify how many elements a list will hold when creating it. Lists elements can be of any Python data type, including integers, floats, strings, booleans, and even other ...Jun 20, 2023 · Overall, creating a dynamic list in Python is simple and flexible, allowing us to add, remove, and modify items as needed. Solution 2: To create a dynamic list in Python, you can use the built-in list data structure. The list in Python is a mutable, ordered collection of elements. Here's an example of how to create and manipulate a dynamic list ...Dec 1, 2023 · Writing List to Files in Python using write () The file is opened with the open () method in w+ mode within the with block, the w+ argument will create a new text file in write mode with the help of write (). The with block ensures that once the entire block is executed the file is closed automatically. Python3. l = ['Geeks','for','Geeks!']Nov 2, 2022 · The easiest way to create a nested list in Python is simply to create a list and put one or more lists in that list. In the example below we’ll create two nested lists. First, we’ll create a nested list by putting an empty list inside of another list. Then, we’ll create another nested list by putting two non-empty lists inside a list ...May 1, 2023 · Time Complexity: O(N) Auxiliary Space: O(N) Method 4: Use the built-in zip function along with a list comprehension. Step-by-step approach: Initialize two lists: one with the keys (test_list) and another with the corresponding values (each value being the concatenation of “def_key_” and the corresponding key).What I want is to add the incremental value to the step to become the new step value p.e. step = 1+1 =2, new step =2, new step = 3, new step = 4 etc. Yes increment the step by one on each iteration. Either use a while loop, or a generator (generators can store state of step, whereas iterators can't) as per the top-two answers here.you can accept a 2D list in python this way ... simply. arr2d = [[j for j in input().strip()] for i in range(n)] # n is no of rows for characters. ... Creating matrix with prepopulated numbers can be done with list comprehension. It …Jan 30, 2019 · Program to cyclically rotate an array by one in Python | List Slicing; Python | Check if list contains all unique elements; Python Program to Accessing index and value in list; Python | Print all the common elements of two lists; Python | Cloning or Copying a list; Python | Ways to shuffle a list; How to count unique values inside a list4 days ago · Creating Lists. A list is created by placing items inside [], separated by commas . For example, # A list with 3 items numbers = [1, 2, -5] # List containing duplicate values numbers = …Jan 6, 2021 ... To create an empty list in Python, you can use one of the following methods: Method 1: Using the square brackets [ ]: You can create an ...Jun 5, 2022 · How to create a Python list. Let’s start by creating a list: my_list = [1, 2, 3] empty_list = [] Lists contain regular Python objects, separated by commas and surrounded by brackets. The elements in a list can have any data type, and they can be mixed. You can even create a list of lists. Nov 16, 2013 · What you are doing here is that, you are trying to assign a list to a string. You cannot do that. If you need to create a lot of lists, first create another single list to store them all. Like this: my_lists = [] for i in range(1,6): new_list = [] for j in range(10): new_list.append(j) Apr 9, 2021 ... Creating a Python list. The list can be created using either the list constructor or using square brackets [] . Using list() constructor: In ...Dec 7, 2021 · Creating Python Lists. Let’s now take a look at how we can create Python lists. To create an empty list, you have two different options: Using the list () function. Using empty square brackets, [] Let’s take a look at what this looks ….

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