How do I figure out what size drill bit I need to hang some ceiling hooks? Python: Repeat elements in a list comprehension? Is it possible for a group/clan of 10k people to start their own civilization away from other people in 2050? Does it make sense? While all the ways provide similar basic functionality, they differ in their syntax and condition-checking time. As mentioned above, if e is an empty list. I had forgotten to add explanation and was about to edit. Is there a word in English to describe instances where a melody is sung by multiple singers/voices? St. Petersberg and Leningrad Region evisa, Avoiding memory leaks and using pointers the right way in my binary search tree implementation - C++. The length of the list is variable from 1-5. How do I get the number of elements in a list (length of a list) in Python? Could ChatGPT etcetera undermine community by making statements less significant for us? How to automatically change the name of a file on a daily basis. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. What's the translation of a "soundalike" in French. Is there a word in English to describe instances where a melody is sung by multiple singers/voices? python - How to repeat one list to match the length of another? - Stack There are several possible reasons for this, starting with its compiling to about 40% more bytecode instructions. We will look at a basic sequence type: list. How to repeat a list's elements in another list content until the length of the second list fulfilled? A car dealership sent a 8300 form after I paid $10k in cash for a car. Repeat values in array until specific length - Georgy. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. Not the answer you're looking for? Is there an exponential lower bound for the chromatic number? islice (iterable, stop) itertools. Is it better to use swiss pass or rent a car? How to generate list with repeating items? 592), Stack Overflow at WeAreDevelopers World Congress in Berlin, Temporary policy: Generative AI (e.g., ChatGPT) is banned. Why do capacitors have less energy density than batteries? This is often called a Python 3 feature, but according to PEP 238, it was introduced all the way back in Python 2.2. 592), Stack Overflow at WeAreDevelopers World Congress in Berlin, Temporary policy: Generative AI (e.g., ChatGPT) is banned. If you want to create independent instances of a mutable object, your xrange syntax is the most Pythonic way to do this. What's the purpose of 1-week, 2-week, 10-week"X-week" (online) professional certificates? What's the translation of a "soundalike" in French. How do you make a string repeat itself in python, Manipulating string to repeat based on the length of another string, How to repeat individual characters in strings in Python, Get all strings matching wanted length by repeating x characters from first string, Repeat string in Python without multiplication. You can use the function with many different data types. Get difference between two lists with Unique Entries. How to normalize a numpy array to a unit vector. minimalistic ext4 filesystem without journal and other advanced features, St. Petersberg and Leningrad Region evisa. Python "while" Loops (Indefinite Iteration) - Real Python Does anyone know what specific plane this is a model of? I am trying to transfer from R to Python, and I'm surprised I have to import a library to do this? You can use numpy.repeat easily. Go slowly and carefully. The function itertools.repeat doesn't actually create the list, it just creates an object that can be used to create a list if you wish! assign value multiple times array, python, Create dynamic Python list with N elements. How do I repeat each element of a list n times and form a new list? It returns the length of an object. Python How to repeat a list's elements in another list content until the length of the second list fulfilled? 592), Stack Overflow at WeAreDevelopers World Congress in Berlin, Temporary policy: Generative AI (e.g., ChatGPT) is banned. You only have to use it in Python 3 (or in modules that have from __future__ import division) but you can use it regardless. Asking for help, clarification, or responding to other answers. I wrote the following simple procedure Term meaning multiple different layers across many eras? The for loop is helpful to get the values within a certain specified range. Connect and share knowledge within a single location that is structured and easy to search. In Python you can iterate over the list itself: There's another built-in function called enumerate(), which returns both item and index: but if you are accessing the list elements anyway, it's more natural to iterate over them directly: If you want to skip the the first element, you can slice the list [tutorial]: can you do another for loop inside this for loop. Remember that Stack Overflow isn't just intended to solve the immediate problem, but also to help future readers find solutions to similar problems, which requires understanding the underlying code. You have to know that Python doesn't have { and } for start and end of loop, instead it depends on tab chars you enter in first of line, I mean line indents. E.g. So you can do loop inside loop with double tab (indent). Do I have a misconception about probability? python - Repeat array until certain length - Stack Overflow 4 Answers Sorted by: 8 You can use itertools.cycle: from itertools import cycle LA = [0,1,2] LB = [ (0,0), (1,0), (2,0), (3,0), (4,0), (5,0), (6,0)] LC = [ (i, j, k) for (i, j), k in zip (LB, cycle (LA))] print LC # [ (0, 0, 0), (1, 0, 1), (2, 0, 2), (3, 0, 0), (4, 0, 1), (5, 0, 2), (6, 0, 0)] "abc", 4 would expect "abca". "Print this diamond" gone beautifully wrong. Why are my film photos coming out so dark, even in bright sunlight? Note that this will copy objects by reference, so may lead to some very difficult to find bugs. If M is greater than the length of the word. This is what I use when I only need to iterate over the string (no join needed then). Was the release of "Barbie" intentionally coordinated to be on the same day as "Oppenheimer"? Not the answer you're looking for? Python's Itertool is a module that provides various functions that work on iterators to produce complex iterators. Repeating list in python N times? You can also use the While loop of Python to traverse through all the elements of the List variable. [duplicate], Best way to extend a list with itself N times, Improving time to first byte: Q&A with Dana Lawson of Netlify, What its like to be on the Python Steering Council (Ep. I'm reading about for loops right now, and I am curious if it's possible to do a for loop in Python like in Java. of course you can have a loop similar to Java: but I never actually used loops like this, or you want to produce another collection from a list, also there are itertools module that covers most of iteration related cases, also please take a look at the builtins like any, max, min, all, enumerate. In this way, the elements in a list get repeated. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. If a crystal has alternating layers of different atoms, will it display different properties depending on which layer is exposed? Updating Variables The programs so far have defined and used variables, but other than in early shell examples we have not changed the value of existing variables. Making statements based on opinion; back them up with references or personal experience. Can someone help me understand the intuition behind the query, key and value matrices in the transformer architecture? Iterate Over A List In Python - Python Guides 592), Stack Overflow at WeAreDevelopers World Congress in Berlin, Temporary policy: Generative AI (e.g., ChatGPT) is banned. What information can you get with only a private IP address. The value of speed of light in different regions of spacetime. This solution is broken for unsorted lists. Python - itertools.repeat() - GeeksforGeeks To learn more, see our tips on writing great answers. In Python, how do I create a string of n characters in one line of code? Instead the same can now be done using range(), however slightly differently than before. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. There are two types of loops in Python and these are for and while loops. Does this definition of an epimorphism work? Circlip removal when pliers are too large. Python provides three types of looping techniques: Python Loops for Loop The graphical representation of the logic behind for looping is shown below: Figure - for loop Flowchart: Syntax: for iterating_var in sequence: #execute your code Example 01: for x in range (0,3) : print ('Loop execution %d' % (x)) Output: The need for this is rare: This is sometimes used to map an iterable into a list of lists: We can see that a_list contains the same range iterator four times: I've used Python for a long time now, and I have seen very few use-cases where I would do the above with mutable objects. Not the answer you're looking for? Find centralized, trusted content and collaborate around the technologies you use most. . Here are some other answers discussing sorting like this. Like the Amish but with more technology? How does your approach differ from the other answers given? How can you manipulate a string to equal the length of another string? Let's see all the different ways to iterate over a list in Python, and performance comparison between them. Why the ant on rubber rope paradox does not work in our universe or de Sitter universe? I have found the repeat function in Numpy, but one is only able to specify number of times to repeat. You could add a switch between the two versions based on the input and output lengths for maximum optimization. of course you can have a loop similar to Java: for i in xrange (len (my_list)): but I never actually used loops like this, because usually you want to iterate for obj in my_list or if you need an index as well for index, obj in enumerate (my_list) Not the answer you're looking for? What does the "yield" keyword do in Python? Why do you prefer this approach? 1.13.1. Does Python have a ternary conditional operator? Not the answer you're looking for? To learn more, see our tips on writing great answers. Loops in Python - GeeksforGeeks This is one way to do it using a list comprehension, though it's increasingly wasteful as the length of the rpt string increases. The outer loop iterates through each element of test_list, and the inner loop iterates K times to repeat each element. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, In Java, that loop is going to skip the first element of your list. Release my children from my debts at the time of my death. [duplicate] Ask Question Asked 10 years, 6 months ago. Ask Question Asked today Modified today Viewed 45 times -2 I have two lists: A = ['a', 'b', 'c', 'd', 'e'] B = ['c', 'a', 't'] How could I repeat the items of B to match the length of A? If the lists are the same size, there is no issue with zip.However, I want to be able to input a single number for a specific list and the script to repeat that number until the longest list is finished. Thanks for contributing an answer to Stack Overflow! Release my children from my debts at the time of my death. The purpose of this question is to maintain the distribution of the original list. I would say - do not try to write Java-like code in python. English abbreviation : they're or they're not. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, Do you just want to sort the final list? Examples >>> np.repeat(3, 4) array ( [3, 3, 3, 3]) >>> x = np.array( [ [1,2], [3,4]]) >>> np.repeat(x, 2) array ( [1, 1, 2, 2, 3, 3, 4, 4]) >>> np.repeat(x, 3, axis=1) array ( [ [1, 1, 1, 2, 2, 2], [3, 3, 3, 4, 4, 4]]) >>> np.repeat(x, [1, 2], axis=0) array ( [ [1, 2], [3, 4], [3, 4]]) islice (iterable, start, stop [, step]) Make an iterator that returns selected elements from the iterable. Then we put this all together. Python def removeThirdNumber (int_list): pos = 3 - 1 index = 0 len_list = (len(int_list)) while len_list > 0: index = (pos + index) % len_list print(int_list.pop (index)) len_list -= 1 nums = [1, 2, 3, 4] removeThirdNumber (nums) Output: 3 2 4 1 Using generators and yield with a while loop to remove and yield every third element Algorithm: Works with any order, sorts on the original order. Python3 list = [1, 3, 5, 7, 9] for i in list: print(i) Output: 1 3 5 7 9 Free Bonus: Click here to get our free Python Cheat Sheet that shows you the basics of Python 3, like working with data types, dictionaries, lists, and Python functions. numpy.repeat NumPy v1.25 Manual Python for loops are a powerful tool, so it is important for programmers to understand their versatility. Python List Length - Initial Commit Not the answer you're looking for? The challenge is simple: given an input list a and another list b, repeat a until it is longer than b. http://en.wikibooks.org/wiki/Python_Programming/Loops. Find centralized, trusted content and collaborate around the technologies you use most. Note: these examples use the new-ish // operator for truncating integer division. One thing about this version is that if length < len(string) then the output string will be truncated. Python Length of List With Counter If the list is less than the maximum_length then the list should be expanded, but should never exceed the max length. Connect and share knowledge within a single location that is structured and easy to search. For example: Edit: actually to my surprise, this is faster than the currently accepted solution (the 'repeat_to_length' function), at least on short strings: Presumably if the string was long, or length was very high (that is, if the wastefulness of the string * length part was high) then it would perform poorly. Do I have a misconception about probability? (If you don't want to modify it in-place, you can copy the list and return the copy, which won't modify the original. There are multiple ways to iterate over a list in Python. Looking for title of a short story about astronauts helmets being covered in moondust. :). What information can you get with only a private IP address? Doesn't an integral domain automatically imply that is it is of characteristic zero? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. Writing a function that repeats a string n times and separates each repetition with another string, Using sep when multiplying strings in Python. The answer depends on what do you need a loop for. Conclusions from title-drafting and question-content assistance experiments Repeat First element of a List of Lists Based on Length, Repeat each item in a list a number of times specified in another list, Repeat elements of list between each other until we reach a certain length, Repeat elements in one list based on elements from another, Repeat elements in nested list with n in another nested list, How to make repeating lists up until a certain number of items, How to loop through two lists with different lengths simultaneously in Python, Iteration over two list of different lengths in python, Repeat list elements based in another list, Replace a column/row of a matrix under a condition by a random number. Find centralized, trusted content and collaborate around the technologies you use most. In R there is the rep function that allows you to repeat a vector, and with the additional argument length.out one is able to specify the length of the final vector/array, e.g. E.g. python - Repeat string to certain length - Stack Overflow Is there an equivalent of the Harvard sentences for Japanese? python multiply list elements in a changing manner, Creating a list of mutable items repeated N times. Can somebody be charged for having another person physically assault someone for them? Can a Rogue Inquisitive use their passive Insight with Insightful Fighting? [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]. Range of 1-4 means that the output will be 1,2,3. n defines the number of times you want to repeat. Multiplying a list gives us the same elements over and over. Connect and share knowledge within a single location that is structured and easy to search. Is there a word in English to describe instances where a melody is sung by multiple singers/voices? Example Get your own Python Server Print each fruit in a fruit list: fruits = ["apple", "banana", "cherry"] for x in fruits: print(x) Try it Yourself The for loop does not require an indexing variable to set beforehand. How do you get the magnitude of a vector in Numpy? Each list will contain the same element e, repeated n times (where n = length of the list). Does Python have private variables in classes? How do bleedless passenger airliners keep cabin air breathable? How can I convert this half-hot receptacle into full-hot while keeping the ceiling fan connected to the switch? Then the following condition must hold true: len (b) < len (ra) <= len (b) + len (a). As an example, call the repeated list ra.