Replace item in list python. 4 µs ± 1.

Replace item in list python Can I replace items in a list based on their position? Yes, the `enumerate()` function allows you to iterate through a list while keeping track of the element’s index, enabling you to replace items based on their position in the list. Python Replace List Elements: Using List Indexing and Slicing Python lists support indexing and slicing, which allow us to access individuals or a series of elements from a Python list. deque (again as suggested by @abarnert), you can achieve the same output without creating the additional list in memory because a deque that can contain a maximum of 0 items will discard everything it receives from the How to replace elements in a particular position nested list python 3? i want to insert elements in a[1] position. Think of list indices as addresses that point to specific items in your list. "," "), tup)) for tup in data] May 19, 2023 · Sort a list, string, tuple in Python (sort, sorted) Reverse a list, string, tuple in Python (reverse, reversed) Sort a list of numeric strings in Python; Get the n-largest/smallest elements from a list in Python; Replace strings in Python (replace, translate, re. You can assign directly to your list of lists if you extract indexing integers via enumerate: Apr 2, 2018 · Yes, strings are immutable in Python. Aug 18, 2020 · I have this python list array: yards = [['85', '110', '90', '130', '115', '105', '95', '87', '85'], ['-', '90 Map operates on each of the elements of the list given. By Aug 27, 2013 · I'm doing something wrong, so far i'm getting import errors like " from contextlib import nested ImportError: cannot import name nested" but besides that, i just tried the line. I have the location of 'xyz' stored in loc: Jul 6, 2019 · How to replace item in lists in a list in Python. Jul 4, 2021 · To Replace Item In List in Python, we can make use of for loops, indexing, comprehension, map and lambda function, while loops, etc. For instance, if we have a list [1, 2, 3, 2, 4] and we want to replace all occurrences of 2 with 5, the desired output would be [1, 5, 3, 5, 4]. Oct 25, 2016 · I have a list of items they may or may not be arbitrarily nested. Going through a list and replacing a string in Python. Let’s explore the various approaches. 16 hours ago · In Python, lists are a fundamental data structure that can be used to store and manipulate collections of data. So in this case, your lambda expression is being called on a tuple, not the elements of the tuple as you intended. sub(pattern, repl, string, count=0, flags=0) Feb 16, 2024 · The list comprehension iterates through the original list and for each fruit, it fetches the corresponding color from the dictionary. Oct 8, 2021 · here is my code below: (display is the list with dashes representing the hidden word) note: I know this code will change the 3rd dash to the letter guessed if correct but I do not know how to write a code that will automatically detect the position in my list. This article will provide a step-by-step guide on how to replace an element in a list in Python. for Loop: Allows manual iteration and checking and provides more control but is less efficient than using ‘ in’. With speed in mind and for a lot of elements: %%timeit arr = ['item1', 'item2', 'item3'] arr = np. e. replace(arr, 'item', 'person') 16. For example: list = ['142', '1567', '153K', '32', '10', '50'] Dec 7, 2013 · How to replace multiple items in a 2D list? 2. A list is a collection of elements enclosed within square brackets []. We transform a and m into a list of pairs map() implementation can be improved by calling replace via operator. May 30, 2024 · In Python, lists are a type of collection data structure that allows you to store multiple elements of different types in a single variable. append(j) However a better way to achieve your aim is to use a list comprehension. But, if list contains just one such item then for @arshajii's solution. list1 = [5, 10, 15, 20, 25, 50, 20] Nov 16, 2014 · Replace items in list, python. Jun 29, 2021 · As such, we’ll look at a few examples which demonstrate how to go about replacing items in a Python list. Before you begin, it’s essential to grasp the basic structure of lists in Python. Sep 4, 2023 · Replacing an item in a list is like swapping an item on your shopping list: it's straightforward when you know how to do it. Let’s understand the code part ‘for items in range(len(products))’; this starts the loop from 0 to the length of the list, which is obtained by passing the list to the len() function and then passing the length value to the range() function. Replacing specific multiple values in list. Lists are zero-indexed: The first item is at index 0, the second at index 1, and so on. Break your task into the constituent parts, namely. Here’s a simplified step-by-step guide on how to replace items in a list using Python: 1. Please see timing in my answer here. This tutorial Apr 12, 2015 · list is a predefined function in python that is used to convert iterables to lists. I have a list like this: Replace items in list, python. Either way (nested or not), I have the element's index location stored in another list. playersScores[playersScores. Python’s list comprehension is a concise way to create lists. Here's a nested list example where I would like to replace 'xyz' with something else, say 123. For my specific situation. This comprehensive guide covers the basics of lists and introduces advanced techniques for re &mldr; What about replace the item if you know the position: aList[0]=2014 An item in a list in Python can be set to a value using the form. Any string operation returns a new string. methodcaller() (by about 20%) but still slower than list comprehension (as of Python 3. zip(itertools. Simple way would be, if you now where the data is: num = [[1,2,3],[4,5,6],[7,8,9]] num[1][0] = <new_value> If you want to replace all 4 or the first 4 in the array, you could iterate it like this: Mar 1, 2023 · That is a pretty simple and easy-to-understand way of replacing a list item in Python. How to replace 2D list values from python dictionary? 1. Replace String From Tuple Inside Sep 27, 2017 · I have a list in Python which contains the number of posted tweets per user profile. Replacing elements in a list. dev. This comprehensive guide covers the basics of lists and introduces advanced techniques for re &mldr; May 30, 2024 · You can replace elements or values in a list by assigning a new value to the list by index in Python. remove is needlessly slow if you've already Sep 19, 2012 · for item in a_list: alist[alist. I have a list of words and some have dashes Nov 23, 2012 · Find and replace string values in Python list. I would like to be able to loop through items (files), and remove the extensions. When you print a Python standard library container such as a list (or a tuple, set, dictionary, etc. 4. x from Python 2. Understanding List Indices. Changing values on a list of lists. index(item)] = item. join(item. You could fix your code as follows: for i in hello: j = i. I think I need to zip my lists to do this, but after that I am at a loss on the best way to go about it. item_to_replace = 5 for lst in NL: try: index = lst. I need to replace the values at particular index in the list2 below with the values from list1 above. Think of indices as addresses for each element within a list. I think you are confusing the repr() representation of the strings with their values. stdtypes documentation. Combine it with the x if y else z conditional expression to modify the items as you want. I tired the following using replace. of 7 runs, 100000 loops each) You should assign the slice to an iterable of the same length as the number of odds: bar[1::2] = [0]*(len(bar)//2) print(bar) # [2, 0, 4, 0, 6, 0, 8, 0, 10] Nov 24, 2023 · You can use the built-in function replace() for string or the map function for other data types in python. alist = [[1,2,3], [4,5,6], [7,8,9]] blist = [[a,b,c], [d,e,f], [g,h,i]] Basically, I want to replace the items in alist with it's blist counterpart. What is the difference between using indexing and list comprehension to replace items in a list? Jun 14, 2013 · How to replace item in lists in a list in Python. And you have to store that new string—either back in the original list, or in a new list. Sep 14, 2018 · Your list doesn't contain any strings with single quotes. Replace element with a list in python. Each number stands for a color. D-cat and cat, I want to replace the item with prefix by the item without a prefix. Mar 10, 2013 · I would like to replace the empty elements in the above list of list (potential size >1000) to "0. Jan 23, 2018 · Processing the items in a list to make a new list calls for a list comprehension. Sep 21, 2015 · In python(2. I would like to replace one of the lists' elements. Replacing one item in a list Jan 20, 2010 · How to replace item in lists in a list in Python. This will show the simplest way to replace item in list Python. However if you use this statement in your loop, the list will be lengthened but enumerate() will only go up to the length of the original list, so 'mango' will get dropped (a hazard of modifying a list while iterating over it). Jul 20, 2017 · You also should not name your variables list, since that is a reserved word in Python. List slicing creates a new list by specifying a range of indices from an existing list. You can use the built-in function replace() for string or the map function for other data types in python. Python makes replacing items incredibly simple using assignment. Oct 19, 2021 · Replace an Item in a Python List at a Particular Index. Replacing items in a list is a common operation in Python programming. This method works if we need to replaces more than one sublist: a=[1,3,5,10,13] a_sub=[3,5,10] b_sub=[9,7] def replace_sub(a, a_sub, b Oct 30, 2017 · Replace items in list, python. Feb 28, 2012 · as i told, i got a list that contains some tuples, i need to replace one of the tuples in the list whit a new one, the tuple that i need to replace is the one that got the first valu equal to the tuple i want to replace it whit. But in Python they are not mutable. To change the list element, you have to access the list. chain. replace feature (didn't know it exists) and it still adds a new line to the text instead of replacing the old one in the file, so i get 2 user. Why Replace an Element in a List? Sep 4, 2023 · Replacing an item in a list is like swapping an item on your shopping list: it's straightforward when you know how to do it. Consequently, the answers to the questions give in-place as well as out-of-place (hm, not sure that's a good inverse of in-place :) answers. Use a dictionary instead if you can. i. That means you have to build a new string to replace the old one. Strings in Python are immutable (meaning that their data cannot be modified) so the replace method doesn't modify the string - it returns a new string. Replacing items in a list using Python. in Statement: The simplest and most efficient method for checking if an element exists in a list. 9). The map() function is used to apply a given function to each item of an iterable (like a list) and return a list of the Feb 4, 2021 · One use case is if you are storing a large number of small sequences where the values rarely change but on few occasions they might want to. Step-by-Step Guide: Python makes replacing list items incredibly straightforward using indexing. Nov 28, 2024 · Appending multiple items to a list in Python can be achieved using several methods, depending on whether you want to extend the list with individual elements or nested collections. Understand the List Structure. ) then the contents of such a container are shown their repr() representation output; this is great when debugging because it makes it clear what type def insert_in_list(a, item_to_replace, list_to_insert): try: index = a. Jan 20, 2017 · In Python 2, if iterating over a large dictionary, use iteritems() instead of items() so that the entire dictionary contents aren't loaded into memory. index(winnerName) will return the index of winner in playersScores list. It can also be used to replace all elements within a list by iterating over the list and assigning the new value to each element. discard(value) if you don't care if the item exists. Aug 26, 2024 · Or consider analyzing data: if you have a list of temperatures and need to correct an erroneous reading, replacement lets you fix the issue directly within the dataset. x[n] = v. The following is an example of using list slicing to replace items in a list: Jul 1, 2014 · If the sublist is a list, I assign list_input a new value since we will need to change the value inside that list also; thus, I call the function again (recursion method as it goes over and over again if there is a list inside a list) and list_input will have a new fixed value that is already changed 'how' into 'X' in the list inside your May 12, 2012 · I have a list of strings like this: Item_has_was_updated_May_2010 Item_updated_Apr_2011 Item_got_updated_Sept_2011 I want to iterate through the list of string and update the last 2 parts of the Feb 7, 2019 · The other solutions use indexing, which isn't necessarily required. You have to bind x to the new string returned by replace() in each iteration: for tag in tags: x = x. . This results in a new list with the mapped values. replace() won't do anything if it doesn't find a match. replace() does not change the string in place -- strings are immutable in Python. Here's a very general answer designed to handle multiple occurrences of multiple values in large dictionaries. append() is only for inserting items at the end of the array. Mar 28, 2024 · This Python tutorial explains how to Replace Python List using methods like List comprehension, list slicing, for loop with examples. x, and in combination with collections. I can find the list item but somehow i can not find the postion in the list so i could replace it? This is what i came up with, but i replaces all items: Jan 4, 2025 · Various methods to replace values in a Python list include using list indexing, for loops, while loops, and lambda functions with the map function. index. In that sense, it's a superset. replace(' ','') k. index(item_to_replace) lst[index] = # your replacement for item_to_replace break except ValueError: continue Jul 24, 2019 · If there are two items e. Likewise , I want to replace all prefix-xxx with xxx. To replace them, just generate a new one containing d lists selected with l items. for place, item in itertools. ) – You can loop through the list to find the item to be replaced and replace it with the new value. old_list = ['the dog ran', 'tomorrow is Wednesday', 'hello sir'] new_list = [('\n' + item) if "Wednesday" in item else item for item in old_list] Aug 26, 2024 · Lists are ordered: Items maintain their position within the list. We’ll begin with a simple example that will work with a list of numbers and multiple items. Now I want to change at a specific area of the list the value to another value (like in my question). Replace multiple list Dec 10, 2011 · I'm trying to replace items in 1 list of lists with items from another list of lists. Below, we Dec 6, 2012 · for item in execlist: if item[0] == mynumber: item[1] = ctype item[2] = myx item[3] = myy item[4] = mydelay item itself is a copy too, but it is a copy of a reference to the original nested list, so when you refer to its elements the original list is updated. In Python, we iterate over a container by actually iterating over it. list. a = [['04\01\1997','alphanum4569874','22','4. So for example randomly generated list: hand = ["A", 3]. split(" ")) or is this better? for item in a_list: alist[alist. Mar 10, 2014 · In case list contains more than 1 occurrences of 'r' then you can use a list comprehension or itertools. How do I replace all occurrences of an item in a 2D list array. Oct 19, 2021 · Learn how to replace an item or items in a Python list, including how to replace at an index, replacing values, replacing multiple values. index(item_to_replace) except ValueError: #if item is not in list return a a[index] = list_to_insert[0] for i in list_to_insert[1:]: a. replace(tag, "") Note that the if statement is redundant; str. (Why isn't there a switch or case statement in python?) Convert your list of tuples to a lookup dictionary (python's switch statement): Feb 22, 2015 · Replace duplicate items from list while keeping the first occurrence. There is no reason to list every list element to find a the elements that need to be replaced. Jan 8, 2021 · You can use this inside your if conditions:. x), comparison of a list with an int will compare Python: Using a list to check items in a seperate list and if present then replace Replace items Jan 14, 2021 · Python Replace Item in List. Python: Modify tuple in list. Share. Python-Replace rows in a column using condition in other column using I have a list, and I want to find the value 20 in the list and if it is present, replace the first instance with 3. sub, re. [avg if x in (mx, mn) else x for x in row]: general conditional list comprehension. Replace element in nested lists of arbitrary depth. Here’s how: Jan 16, 2013 · You can use the six module to simulate the behavior of map in Python 3. python: how to replace a string in a list of string with a list of strings? 2. Examples. python replacing item in list. Python list indices start at 0 and go all the way to the length of the list minus 1. extend() method How to replace an item in a list with a dataframe column if column contains the item. Method 3: Using the map() Function. Definition of the Concept. As immutable objects, you need to assign the strings to elements in your list of lists. For loop replacing list elements. Feb 3, 2017 · You are printing the results of the replacement, but do not change the list contents. Mar 28, 2024 · Look at the output; the item ‘MSI Laptop’ in the list of products is replaced by the new value ‘Air 15 MacOs Laptop’. Replacing an element of a list with multiple values. Jun 13, 2014 · @mgilson: The other question I referenced doesn't specify a "out-of-place" constraint either. One of the most common operations performed on lists is replacing an element. Conclusion. eg. Dec 14, 2019 · Is there any solution to replace items with a specific value in a dict of nested list and dicts in python ? for example: Input : item_to_be_replaced = 'a' replaced_with = 'z' di = {"a": "A",. remove unless your removal criteria is actually to remove an element with a particular value, when you don't know/care where it is in the list. from operator import methodcaller list(map(methodcaller('replace', '[br]', '<br />'), words)) W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Thus you will need to do a map of some sort. You can use it to replace items in a list by creating a new list that includes the modified segments. If you want it to replace in all sublist then remove the break statement from try block. Jun 6, 2023 · Using indexing or slicing. index(winnerName)] = winner Here playersScores. ( the first value inside of the tuples is tup[0]) – Apr 8, 2021 · In this article, I walked you through 4 methods to replace items in a Python list that are indexing, for loops, list comprehensions and slicing-shuffling. Replacing Items Using Assignment. map(B) #convert the list to a pandas series temporarily before mapping D = list(C) # we transform the mapped values (a series object Sep 8, 2023 · No you wouldn't alter the "content" of the list, if you could mutate strings that way. Replacing an item in a list is a fundamental operation in Python programming. It doesn´t matter if the original entry reads "NSW = 500" or "NSW = 501". 0. Hot Network Questions May 1, 2023 · Replacing Items in a List with Python Learn how to replace items in a list using Python, including step-by-step instructions and code examples. 0']] b = ['alphanum1','alphanum2'] for idx,item in enumerate(b): for i Step-by-Step Explanation: How to Replace Items in a List Python. Here’s an example: my_list = ['alpha', 'beta', 'gamma'] index_to_replace = 1 new_value = 'delta' my_list = [new_value if idx == index_to_replace else val for idx, val in enumerate(my_list)] print(my_list) Output: ['alpha', 'delta If you wish to remove an item from the set by value and replace it, you can do: data. Note that this approach works only if the elements to be replaced are hashable. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. replace(" ", "-") NOTE: The above solution only updates the 1st occurrence in this list, as David suggested, use list comprehension to do the above task. In the last of these, in every iteration you construct a new temporary list of size n-1, and then you construct a list of size n, which is why it takes nearly twice as long as the previous one (construct a list of size n-1 and then append an element). How am I supposed to do that without indices?" Simple. Feb 8, 2019 · . Let’s summarize each method: List indexing: We use the index number of a list item to modify List comprehension is the right way to go, but in case, for reasons best known to you, you would rather replace it in-place rather than creating a new list (arguing the fact that python list is mutable), an alternate approach is as follows Jun 25, 2013 · import pandas as pd A = ['A','B','A','C','D'] #list we want to replace with a dictionary lookup B = {'A':1,'B':2,'C':3,'D':4} #dictionary lookup, dict values in B will be mapped to entries in A C = (pd. data. Replace element of a Aug 26, 2024 · That’s where the ability to replace items comes in handy. Replacing values in a Python dictionary? 0. Replace list value in Python dictionary. replace doesn't work in-place, it returns a copy. In case you want to replace values in place, you can update your original list with values from a list comprehension by assigning to the whole slice of the original. re. For example, if someone chose 1 in alist, I want to replace it with the same index from blist which would be a. May 1, 2023 · Learn how to replace items in a list using Python, including step-by-step instructions and code examples. Let’s look at some examples of usage of the above-mentioned methods to replace items in a list in Python. get # For faster gets. Sep 11, 2017 · You can use the random module and use the random. input. sub as the third parameter requires a string. Remove Duplicates in list in python. 0'],['07\01\1997','Anee_69213654','23','2. Dec 10, 2013 · What is the pythonic way to search through the given list ['a', 'b', 'c'] for the element b replace it and insert multiple items b1, b2, b3 so that the list finally reads as ['a', 'b1', 'b2', 'b3', Apr 19, 2016 · the items in list1 coincide with the values in the column Date and I want to replace them with the items that are in list2. If you have a closer look on the replace method (for strings(!)), you'll see that you are not only not changing the list but also not changing the strings you are getting for o in Originals. You can alternatively use a list comprehension: def replace(lst, dictionary): return [item if not item in dictionary else dictionary[item] for item in lst] Jul 7, 2020 · This will replace only the first occurrence of item_to_replace. Oct 20, 2014 · To find an item with a specific value in a python list, use list. Replace an item in a list by another item Python: Replace an element in a list with an 3. Th Aug 10, 2021 · The string in the dict is not being replaced, because you never changed it. Overview: Explore essential techniques in Python for replacing values within lists. Python: Replace Item in Tuple Converted to List. g. (This doesn't matter for Python 3 since items() basically does what iteritems() did in Python 2. Really simply, you could check if the value is in the new list, else you can append x. [d[item] for item in l] If you are not sure that all items in l are keys in d you can add test before trying to get from d: [d[item] for item in l if d. Mar 7, 2022 · I have a list which will add random items in any order. In principle, the replacement you want can be done with list[n:n+1] = replace_with. Replacing An Element in a Python List Using Dictionary. Python lists are ordered, meaning that we can access (and modify) items when we know their index position. x = [animal. Replace an item in a list. If you have several values to replace, you can also use a dictionary: replacer = replacements. Ideal for most cases. D-cat has to be replaced with cat. wrapping your code in a list comprehension would do it: newData = [tuple(map(lambda i: str. Jan 4, 2025 · Various methods to replace values in a Python list include using list indexing, for loops, while loops, and lambda functions with the map function. Mar 7, 2019 · Suppose I have a pandas df: import pandas as pd ex = pd. With this approach, you can replace a value of a list at any random index without accessing all elements of the list. Oct 8, 2015 · I've got a list of lists (Tilemap) with different numbers. I'm guessing you want to keep track of the guesses till all letters are guessed (or till number of guesses) so your loop should have a temporary list and then loop through board to add the new guesses(if found) something like: Using if item == my_tuple[0], in a general case sounds like you are making a switch statement that you want to apply to each item in your list. For a small but non-zero length sequence, the memory consumption of tuple (60-bytes for one-element) vs list (104 bytes) and make a difference. Each operation is straightforward per se , but you should be able to master them by choosing the most appropriate and efficient method while solving more complex challenges, in preparation 4 days ago · In this article, you will learn how to replace an element in a list in Python, including various methods to replace an item in a list and practical examples for better understanding. Removing duplicated items from a list in python. char. 07 µs per loop (mean ± std. Feb 17, 2021 · This list of lists contains tuples with index as first item and value as second item. def sum_digits(number): # Convert the number into a string (10 -> "10"), # iterate over its characters to convert each of them # back to an integer, then use the `sum()` builtin for # summing. shuffle, sample) Add Feb 16, 2024 · Combined with list comprehension, this method provides a succinct way to replace items based on their index. Hot Network Questions Rail splitter with LM324 Feb 22, 2012 · The method str. You changed the loop index, not its data source. Here’s an example: Dec 3, 2019 · You may need a function that runs first to 'examine' the list of lists (e. Nov 29, 2024 · Which Method to Choose. But cause my list doesnt look like [a, , z] but [[a, , z]] the method mentioned does not affect anything. csv h1,h2,h3 data of database,a,v gg,word or words/word,gdg asd,r,rank I have to replace in a list the multiples of 5 by the number + x. It involves updating or modifying the value associated with a specific element within the list. add Nov 27, 2024 · The resulting list new_list contains the same items as the original list, but with all occurrences of 3 replaced with a function that returns 10. If you had a list of objects you knew were mutable, you could do this as long as you don't change the actual contents of the list. If you want to update or replace a single element or a slice of a list by its index, you can use direct assignment with the [] operator. subn) Shuffle a list, string, tuple in Python (random. Each item in a list is called an element, and elements are separated by commas and enclosed within square brackets []. Handling simpler more specific cases and/or with small dictionaries -- like your example -- could be done significantly faster. 4 µs ± 1. The inserted elements are in list b. Using the python replace list values using a tuple. I don't know how to appropriately loop through items in the list when re. Feb 16, 2024 · Method 1: Using List Comprehension. Learn how to replace an item in a list using various methods in Python programming, including indexing, list comprehension, and more. choice() method on the 2nd list to return a random element of the list Jan 12, 2015 · This has some trickery so you don't get data analysis of data analysisbase when replacing data:. Obviously, I can iterate over the list using say i,j - but I was sure python had some itertools etc methods which could be very fast. replace(i, ". from_iterable with a generator expression. replacing a number with the sum of its digits; doing that for a list of numbers. How to Use List Slicing to Replace Items in a List. This involves identifying an item with a specific value and substituting it with a new value. I am looking for a way to replace an item with another item & at the same time keep the same index position, without knowing which index position it will originally be in. You could define a function that loops over the list to see if any of the entries have digits using using isdigit() like so Jul 3, 2012 · How to replace item in lists in a list in Python. Both list1 and list2 will be of same length and indices in the list of lists will be with in the range: Apr 6, 2020 · Simply row = would just rebind the loop variable without affecting the list object that is still indexed by table. 2. With the concept of indexing and the power of the equals sign = , you can easily control what goes in and out of your Python list. randint() method to generate a random number between 1 and 100 as a heads and tails coin toss to decide whether to replace the value or not and then use the random. Feb 16, 2024 · When working with Python lists, one might encounter the need to replace elements by their values. Jul 9, 2012 · Never ever use list. How to replace items in list with a keys from dictionary in Dec 20, 2017 · In this case the item the contains "NSW" (capitals are important) in any form should be replaced by "NSW = 0". Using extend method (Adding multiple items from iterable)The list. This is a highly readable and efficient method for small to medium-sized lists. insert(index + 1, i) return a it's a bit long, but i don't know if there is a better way to insert. Why Replace an Element in a List? Nov 24, 2023 · This tutorial will show you how to replace certain values, strings or numbers in a given list. has_key(item)] 3. Thus if you use list as a keyword, you will be losing the functionality of the built-in function list – Bhargav Rao Jun 6, 2017 · You can use list comprehension as mentioned in the answers, but in your code board will always reset with every guess. Python - how to replace string in a list? 0. The first two methods modify an existing list whereas a list comprehension creates a new list with the specified changes. replace('D-cat','cat') for animal in x] Expected result: Here is another way to do this. Jan 4, 2025 · Various methods to replace values in a Python list include using list indexing, for loops, while loops, and lambda functions with the map function. count(0), list): if "foo" in item: item = replace_all(item, replaceDictionary) list[place] = item print item Share Improve this answer Oct 31, 2017 · For, example if I wanted to make every second uppercase and lowercase like original_list = ['FisH', 'Dog', 'cow', 'piG'] desired_list = ['fish', 'DOG', 'cow', 'PIG Jul 2, 2009 · Replace items in a list using a dictionary. 1. Fairly self-explanatory. So in Date 19990506 is replaced with 1999201 and 19990607 is replaced with 1999232. index(item)] = '-'. Before we dive into replacing items, it’s crucial to grasp the concept of list indices. DataFrame({'Title': ['Data Scientist', 'Data Analyst', 'Data Engineer'], 'Skills': [['Python', 'R ', 'C Jan 27, 2015 · Replace items in list, python. for idx, path in enumerate(m['files']): if "replace" in path: m['files'][idx] = new_path print(m['files'][idx]) path is simply a local variable. 5. Jul 13, 2018 · You are unpacking from the list in for loop and creating 3 variables name, appt and salary. With this variables it isn't possible to easily change your data structure. Or, you can use a list comprehension with a conditional to check for the value to be replaced and replace it accordingly. This is usually the simplest and fastest way to modify a list element or slice. If your removal criteria is based on position (as in this case) or any other kind of criteria, there is always a better way than "find the element I want to remove then call remove". Python lists are zero-indexed, meaning the first item has an index of 0, the second item has an index of 1 Nov 27, 2017 · I am trying to replace parts of file extensions in a list of files. remove(value) #data. Method 2 – Python Replace Element in List using Python enumerate() Another way of achieving our goal would be to use enumeration with the enumerate() function: Dec 7, 2015 · Don't change list when you are looping in, because iterator will not be informed of your changes. Think of indexing like assigning numbers to each item in your list, starting Jul 13, 2019 · Replace list value in Python dictionary. 7. If you wanted to use a function: Jan 5, 2025 · map function: With the help of the map function we can apply a function on every element of the Python list and replace the values of list elements. Replace an item in a list based on user input. 00" and I was wondering what is the most pythonic (one liner would be awesome) to achieve this. to flatten it or at least to build up a reference of entry to location). 3. List comprehensions, the replace() method, and for loops are all powerful tools for replacing items in a list. "But wait", you say, "For each of those elements of a, I need to work with the corresponding element of m. Series(A)). What you need is extract a list from data and access it by indexing: Apr 18, 2016 · What is the difference between Python's list methods append and extend? Hot Network Questions Do interaction terms violate the linearity and additivity assumptions in linear regression? Jun 8, 2014 · I can't seem to work out how to get the code to check if the number strings contain any more number . Jan 10, 2022 · I have two lists A =[2,3,4,5,33,42,21] and B = [1,11,35,48,19] I want to randomly delete two items of list B and replace with two random items from list A for 200 iteration. names with different values, wich should happen :( -- From the documantation Sep 24, 2018 · Because str. You can replace an item in a Python list using a for loop, list indexing, or a list comprehension. csac qzfwtx nyfix wkspb oezg pdwqz agcv ojrpgy myye nqbx