Replace element in list with element from another list - Python Ask Question Asked 8 years, 8 months ago Modified 8 years, 8 months ago Viewed 1k times 0 I have a list named rule.start. Here is an example of Replace list elements: Replacing list elements is pretty easy. rev2023.7.24.43543. I want to replace replace_this with [2, 3]. If a crystal has alternating layers of different atoms, will it display different properties depending on which layer is exposed? Python Program to swap two elements in a list | Replace an Element in Python 3.1.2 (r312:79147, Apr 15 2010, 15:35:48) By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. I want to replace an element in a list with multiple elements. An example of data being processed may be a unique identifier stored in a cookie. How do I iterate through two lists in parallel? Breaker panel for exterior post light is permanently tripped. Why is a dedicated compresser more efficient than using bleed air to pressurize the cabin? Can I spin 3753 Cruithne and keep it spinning? Find centralized, trusted content and collaborate around the technologies you use most. After replacing it must be: Of course, it is possible to do with slicing (I'm sorry that I didn't write it in the question), but the problem is that it is possible that you have more than one replace_this value in the list. I might be a little to the party, but a more Pythonic way of doing this is using a map and a list comprehension. Python | Pandas Series.replace() - GeeksforGeeks [GCC 4.4.3] on linux2. Given two lists (a and b), I'd like to replace three elements of list 'a' with three elements of list 'b'. 592), Stack Overflow at WeAreDevelopers World Congress in Berlin, Temporary policy: Generative AI (e.g., ChatGPT) is banned. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Conclusions from title-drafting and question-content assistance experiments replace item in a string if it matches an item in the list, Python: replace string, matched from a list, English abbreviation : they're or they're not. Is there a way to speak with vermin (spiders specifically)? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, Replacing an element from one list with all elements in another list, Improving time to first byte: Q&A with Dana Lawson of Netlify, What its like to be on the Python Steering Council (Ep. How does hardware RAID handle firmware updates for the underlying drives? This is the case because you are only changing the temporary variable a. First create a mapping from one list to another: my_mapping = dict (zip (x, y)) The zip part is mainly a formality: dict expects the argument to be a sequence of pairs, rather than a pair of sequences. This dosen't quite hit it, you can pass a generator comprehension instead of a list comprehension to "chain". Improve this question. Python : How to replace single or multiple characters in a string Can consciousness simply be a brute fact connected to some physical processes that dont need explanation? Replacing items in 1 list to items in another list in python. Why would God condemn all and only those that don't believe in God? What is the smallest audience for a communication that has been deemed capable of defamation? Find centralized, trusted content and collaborate around the technologies you use most. Python: Replace an element in a list with an element from another, Replace elements of a list by elements of other list, Replacing elements in a list of lists, with elements from another list, Replace specific values in a list with values from another list, Substituting elements of a list with elements of another list. Replace an Element in Python List | Delft Stack When laying trominos on an 8x8, where must the empty square be? Replacing elements between lists in python. I was not able to determine if that case was identical to mine or not. How To Delete An Element From A Python List - Python Guides Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. You can then use the syntax below to perform the replacement (note that unlike the previous scenarios, its not necessary to use quotes around numeric values): As you can see, the numeric value of 22 was replaced with 99 in 2 locations: DATA TO FISHPrivacy PolicyCookie PolicyTerms of ServiceCopyright | All rights reserved, Replace Characters in Strings in Pandas DataFrame, Replacing multiple items with another item, Replacing multiple items with multiple items. How do you manage the impact of deep immersion in RPGs on players' real-life? Lists are mutable so you probably want to replace list items, not the lists themselves: If you want to swap lists rather than replace them then: If you want to exchange the two, you could simply do this: The way you asked this is to just change the array from trying to assign a list to a specific element in. How to match and replace list elements in Python? Is this mold/mildew? Let's summarize each method: List indexing: We use the index number of a list item to modify the value associated with that item. Any one of which if changed, it would later on change the others as they would share the same memory location. You can replace an item in a Python list using a for loop, list indexing, or a list comprehension. Python: how to replace an element in a list with all elements from another list? We use the enumerate() function in this method. ; not using secondary_list.copy(). Using robocopy on windows led to infinite subfolder duplication via a stray shortcut file. How can I avoid this? Lists are mutable so you probably want to replace list items, not the lists themselves: a [2] [:] = a [0] If you want to swap lists rather than replace them then: a [0], a [2] = a [2], a [0] Share. Could ChatGPT etcetera undermine community by making statements less significant for us? I'm going to use a simple example, but basically x is another variable and isn't linked to the list element. In the circuit below, assume ideal op-amp, find Vout? Can a Rogue Inquisitive use their passive Insight with Insightful Fighting? python: how to replace a string in a list of string with a list of strings? You can then use a list comprehension to perform the replacement: Youll now see that Banana was replaced with Pear in 3 locations: What if you want to replace multiple items with another item? As immutable objects, you need to assign the strings to elements in your list of lists. Thanks for contributing an answer to Stack Overflow! Exercise. We could replace elements in a Python list in several ways. 592), Stack Overflow at WeAreDevelopers World Congress in Berlin, Temporary policy: Generative AI (e.g., ChatGPT) is banned. The main idea is that the inner loop is iterating through the inner loop and using the simple lambda function to perform the replacement. Replace element in list with element from another list - Python To learn more, see our tips on writing great answers. Then apply this mapping to every member of r using a list comprehension: Dictionaries are the best option for this. pythonic way of replacing the content of list of list? Replace elements of a list by elements of other list, Substituting elements of a list with elements of another list, Replacing items in a list with items from another list in python, Anthology TV series, episodes include people forced to dance, waking up from a virtual reality and an acidic rain. How to match and replace list elements in Python? minimalistic ext4 filesystem without journal and other advanced features. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. Housing Secretary Michael Gove has delivered a speech focusing on proposed planning reforms. So. Method #1 : Using replace () + list comprehension The combination of above functionalities can be used to perform this task. How does hardware RAID handle firmware updates for the underlying drives? Geonodes: which is faster, Set Position or Transform node? How can kaiju exist in nature and not significantly alter civilization? Now go upvote one of the more readable answers. It inserts the secondary list into the primary list at the correct index: Not only is it redundant, but it also just does the same as above. It will not turn on. How many alchemical items can I create per day with Alchemist Dedication? Example 1: Replace a Single Value in a List The following syntax shows how to replace a single value in a list in Python: #create list of 4 items x = ['a', 'b', 'c', 'd'] #replace first item in list x [0] = 'z' #view updated list x ['z', 'b', 'c', 'd'] Example 2: Replace Multiple Values in a List How to Replace Items in a Python List - Data to Fish How to Replace Items in a Python List July 3, 2021 You can use a list comprehension to replace items in a Python list: my_list = ['item 1', 'item 2', 'item 3',.] The "more pythonic" part isn't really a generic one considering the fact that, @Austin, Possibly. 2 Answers. Learn / Courses / Introduction to Python. The problem in your code was because of two reasons in the following line: If you had multiple occurrences of 'black', then this would copy the secondary list there. Conclusions from title-drafting and question-content assistance experiments Python: Replacing item in a list of lists, Python: Change an element in a list of lists. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. @Istvanb if you've a python list, then that's all you can do, just in case you've a numpy array you can do something like you want to do, see the updated answer. How to replace one element from a list with several element from another list? Replace list elements | Python - DataCamp numeric, str or regex: numeric: numeric values equal to to_replace will be replaced with value str: string exactly matching to_replace will be replaced with value regex: regexs matching to_replace will be replaced with value list of str, regex, or numeric: 592), Stack Overflow at WeAreDevelopers World Congress in Berlin, Temporary policy: Generative AI (e.g., ChatGPT) is banned. How do I figure out what size drill bit I need to hang some ceiling hooks? Making statements based on opinion; back them up with references or personal experience. Airline refuses to issue proper receipt. I think that it would be better to use itertools.chain, but I'm not sure. Replacing items in 1 list to items in another list in python. Currently I am using an expression like this: As I need to do such operations very frequently with lots of different arrays I am wondering if there is a more compact solution for this problem (the number of elements I need to replace is always 3 though). (Bathroom Shower Ceiling). Not the answer you're looking for? temp is a sublist of the original list, reverse it in place. Method 1: Using List Indexing We can access items of the list using indexing. Airline refuses to issue proper receipt. How can I replace elemts of a list with other elements. I would love to keep the list comprehension, as this seems to be more suitable than a.extend(('b', 'c')), for example. if I wanted to replace 'r' with 'a' and 'b': It can be done fairly easily with slice assignment: Also, don't call your variable list, since that name is already used by a built-in function. How difficult was it to spoof the sender of a telegram in 1890-1920's in USA? By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. I have silly question but struggling with this shit too long: How to replace just one element of the 2D list? If I have an array having more than one list. A Holder-continuous function differentiable a.e. How to replace one element from a list with several element from another list? May I reveal my identity as an author during peer review? How to replace one element in 2D list? How to replace an element within a list within a list (a list of lists)? Does ECDH on secp256k produce a defined shared secret for two key pairs, or is it implementation defined? We and our partners use cookies to Store and/or access information on a device. Definition and Usage The replace () method replaces a specified phrase with another specified phrase. Answer (1 of 22): If you know the index of the item that you want change , then do this: [code]a_list = ["a","b","c"] a_list[2] = "z" #new list will be like ["a","b . How to avoid conflict of interest when dating another employee in a matrix management company? Simply subset the list and assign new values to the subset. This is the most basic and the easiest method of accessing list elements. Utilizing index 0, we can change the first item on the list. Looking for story about robots replacing actors. You have to change the list element directly in order to alter the list. Exercise 1: Reverse a list in Python Exercise 2: Concatenate two lists index-wise Exercise 3: Turn every item of a list into its square Exercise 4: Concatenate two lists in the following order Exercise 5: Iterate both lists simultaneously Exercise 6: Remove empty strings from the list of strings Anthology TV series, episodes include people forced to dance, waking up from a virtual reality and an acidic rain. Your code is almost correct, you only need to add 1 to list.index ('b'): In [14]: l = ['a', 'b', 'c', 'e'] In [15]: l [l.index ('a'):l.index ('b') + 1] = 'd', In [16]: l Out [16]: ['d', 'c', 'e'] Method 1: Replace Elements Equal to Some Value The following code shows how to replace all elements in the NumPy array equal to 8 with a new value of 20: #replace all elements equal to 8 with 20 my_array [my_array == 8] = 20 #view updated array print(my_array) [ 4 5 5 7 20 20 9 12] Method 2: Replace Elements Based on One Condition Is saying "dot com" a valid clue for Codenames? In the circuit below, assume ideal op-amp, find Vout? Find centralized, trusted content and collaborate around the technologies you use most. A car dealership sent a 8300 form after I paid $10k in cash for a car. Sorted by: 2. Using list indexing The list elements can be easily accessed with the help of indexing. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. How feasible is a manned flight to Apophis in 2029 using Artemis or Starship? How do I proceed? You probably meant to do this: gamewords = newgamewords [:] # i.e. What information can you get with only a private IP address? Can I opt out of UK Working Time Regulations daily breaks? Then apply this mapping to every member of r using a list comprehension: new_r = [my_mapping [elem] for elem in r] Share. To learn more, see our tips on writing great answers. Python3 test_list = ['Gfg', 'is', 'best', 'for', 'Geeks'] print("The original list is : " + str(test_list)) If we want to replace the first item of the list we can di using index 0. So for example I have the list a = ['b', 'c']and want to replace 'b' with 'd', 'e' which would give me the list a = ['d', 'e', 'c']. 7 Efficient Ways to Replace Item in List in Python Not the answer you're looking for? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Physical interpretation of the inner product between two quantum states. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, @charlottechahin one more update (even simpler to swap first and last element), hey thanks for the answer.. Replace Item in List in Python: A Complete Guide - Career Karma Thanks again. In python, what is the best way to replace an element in a list with the elements from another list? What should I do after I found a coding mistake in my masters thesis? Breaker panel for exterior post light is permanently tripped. What is the simplest method for replacing one item in a list with two? We will change the element at the index 0 from 5 to 20. python - Replacing an element from one list with all elements in Is saying "dot com" a valid clue for Codenames? Why would God condemn all and only those that don't believe in God? May I reveal my identity as an author during peer review? Replace list elements. Why would God condemn all and only those that don't believe in God? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. Course Outline. This is the simplest and easiest method to replace values in a list in python. Changing values on a list of lists. To learn more, see our tips on writing great answers. gamewords = list (newgamewords) I find the latter more readable. How to Replace Values in a List in Python - Statology To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Line integral on implicit region that can't easily be transformed to parametric region. Can a creature that "loses indestructible until end of turn" gain indestructible later that turn? is absolutely continuous? Python: how to replace an element in a list with all elements from another list? You can assign directly to your list of lists if you extract indexing integers via enumerate: More Pythonic would be to use a list comprehension to create a new list. Connect and share knowledge within a single location that is structured and easy to search. Making statements based on opinion; back them up with references or personal experience. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. The simplest and most straightforward way to replace elements inside a list in Python is to use this. Can a Rogue Inquisitive use their passive Insight with Insightful Fighting? Connect and share knowledge within a single location that is structured and easy to search. I want to replace an element in a list with multiple elements. @lu5er, Replace elements in a list of lists python, Improving time to first byte: Q&A with Dana Lawson of Netlify, What its like to be on the Python Steering Council (Ep. Was the release of "Barbie" intentionally coordinated to be on the same day as "Oppenheimer"? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. After printing out x it is still the same as list, but not as follows: Why is the change not being reflected in list? In the circuit below, assume ideal op-amp, find Vout? Since all the elements inside a list are stored in an ordered fashion, we can sequentially retrieve its elements. Thanks for contributing an answer to Stack Overflow! list = [1,2,3] Do US citizens need a reason to enter the US? @charlottechahine don't forget to upvote anything you feel was helpful and mark an answer. How can I animate a list of vectors, which have entries either 1 or 0? to Does glide ratio improve with increase in scale? Is it appropriate to try to contact the referee of a paper after it has been accepted and published? Connect and share knowledge within a single location that is structured and easy to search. Syntax string .replace ( oldvalue, newvalue, count ) Parameter Values More Examples Example Replace all occurrence of the word "one": But what your list contains numeric data? What would naval warfare look like if Dreadnaughts never came to be? How to replace one element in 2D list? : r/learnpython - Reddit 2. This simplifies the code when you need to replace fair amount of elements, but not when you need to replace only a couple of them. Term meaning multiple different layers across many eras? And, in fact, also the other solution does not work with nested lists. rev2023.7.24.43543. Asking for help, clarification, or responding to other answers. Here's an option using an intermediate result list: You should create another list and add primer list elements and secondary list elements. Replacing element in list with multiple elements [duplicate], list.extend and list comprehension [duplicate], Improving time to first byte: Q&A with Dana Lawson of Netlify, What its like to be on the Python Steering Council (Ep. Release my children from my debts at the time of my death. ; If you had multiple occurrences of 'black', then this would copy the secondary list there. Connect and share knowledge within a single location that is structured and easy to search. Making statements based on opinion; back them up with references or personal experience. If Phileas Fogg had a clock that showed the exact date and time, why didn't he realize that he had reached a day early? It returns a enumerate object that also contains the counter together with the elements. Which denominations dislike pictures of people? Is it a concern? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, you are making a copy of things in list by. Replace multiple list elements at the same time (Python), Improving time to first byte: Q&A with Dana Lawson of Netlify, What its like to be on the Python Steering Council (Ep. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. This can be bewildering at first. In this list, all elements are equal to an element from another list called com.empty. 3. I have a list in Python with certain elements. Asking for help, clarification, or responding to other answers. Can a Rogue Inquisitive use their passive Insight with Insightful Fighting? How many alchemical items can I create per day with Alchemist Dedication? Python 3.1.2 (r312:79147, Apr 15 2010, 15:35:48) [GCC 4.4.3] on linux2. To learn more, see our tips on writing great answers. I want to have another list that relates elements in a list like: so that a new list will be created with the the corresponding elements from y whose elements are in x. Should I trigger a chargeback? Python String replace() Method - W3Schools Which denominations dislike pictures of people? They all return a new string, so you have to reassign the string returned by replace: for t in To_remove: for i in range (len (Originals)): Originals [i] = Originals [i].replace (t, "") +1. Python: Replace Item in List (6 Different Ways) datagy