Python index multiple elements It returns the index of the first occurrence of the element we are looking for. CSS_SELECTOR, "div[id='contents'] a[href]") However, incase of css_selector: class attributes can be shortened as . Let us see how multiple elements can be displaye Oct 18, 2021 · I know that this question occured multiple times in different variations, but I couldn't find anything that actually matched my problem. 0 occurs in the list. append(L. One of the most basic ways to get the index positions of all occurrences of an element in a Python list is by using a for loop and the Python enumerate function. Remove using pop() The list. How can I get multiple values from this array by index? For example, how can I get the values at the index positions 1, 4, and 5? I was trying something like this, which is incorrect: Jun 9, 2011 · If you need to perform multiple lookups on a list, it may be more efficient to compile a dictionary with all of the positions of every distinct element. Dec 10, 2020 · How to retrieve multiple elements from a series when the index is customized Python - When the index values are customized, they are accessed using series_name[‘index_value’]. array to glue the data access to Python. This is how the solution would look as code: 1. index(x) will only return the index in the list of the first item whose value is x. ) Jul 7, 2015 · You want to pass in the optional second parameter to index, the location where you want index to start looking. After we remove the element at index 0, all the other elements shift, and their indices change because the element at index 1 is now at index 0 and so on. index() method is the simplest way to find the index of an element in an array. I haven’t been able to find a good solution for this problem on the net (probably because switch, position, list and Python are all such overloaded words). for i in range(len(L)): j = R[i] N. Jul 17, 2013 · can anybody please give me a hint how to aggregate (sum up) specific elements of multiple lists? For example I have 20 lists with a similar name pattern, each representing consumption spending over time (i. 1. Mar 14, 2011 · I want to iterate over my list and do something with multiple elements, not just one element. You are welcome. index('i') // i_idx -> 12 i_idx = test. This method is fast and requires no additional memory or function calls. Using Array Concatenation (+ Operator) You can also append to an array by concatenating it with another array or iterable using the + operator. May 1, 2016 · For list we can get index of element list_name. . nonzero-. , [4, 5, 6]). The ‘index_value’ passed to series is tried to be matched to the original series. List a contains 8 values (all different) followed by 16 zeroes which repeats until the end of the list, li Apr 17, 2023 · Combining multiple lists into a single list is a common operation in Python, and there are various approaches to achieve this task. index(element)]) It should get as arguments a list of text values to send into <input type="text">, <input type="password"> and <textarea> elements. Aug 30, 2011 · 2) You can use the C API to copy the elements using PyTuple_GET_ITEM which accesses the internal array directly, but be warned that using the C API is not trivial and can introduce a lot of bugs. Nov 19, 2014 · I've done this with BeautifulSoup but it's a bit cumbersome, and I'm trying to figure out if I can do it directly with Selenium. g. So for example I have the array a = Apr 3, 2015 · How to set the same value in multiple index of array once python? 0. One does not need to do it for Python 3 as the list comprehension has been changed to do that. the buffer interface of array. 0 at index 2, and at index 9, then . The simplest way to do this is by using a loop. I want to take the first element and some elements after it (they could be sequential or maybe the 3rd element from the one returned). To do this we can: Map an index onto each element. index docs, signature looks like this. index() to get the indices but that only returns the first value. array(a) # numpy version I want to get 1st to 100th, 201st to 300th, 401st to 500th elements and make them into a new array. So far I have: You are using . in1d with np. So, you can loop until you stop finding the substring in your Jan 7, 2025 · In this example, we find an element in list python, the index of an element of 4 in between the index at the 4th position and ending with the 8th position. For example, I have a list containing some same values like: mylist = [(A,8), (A,3), (A,3), (A,3)] I want to return: index_of_A_3 = [1, 2, 3] Jun 16, 2014 · What you're attempting to do yourself is memory friendly, with the downside that it mutates your old list, but popleft is not available for lists in Python, it's a method of the collections. Approach 1: Iterating Sep 3, 2016 · PHP arrays are actually maps, which is equivalent to dicts in Python. CSS_SELECTOR, "div#contents a[href]") Jan 2, 2025 · Here, we use the outer index (m[1]) to access a specific sublist (e. start(), m. 2. For more on list operations, visit Flattening Lists in Python. Feb 25, 2024 · To remove multiple elements from a list in Python, we can use several methods like list comprehension for filtering elements, the remove() method for specific values, the filter() function to create a new list based on a condition, the del keyword for removing elements by index, and list slicing for selectively keeping elements. Here are two simple ways to do this: Sorry if this has already been asked, I couldn't find it anywhere. index('item') then remove the corresponding value: del item_list[ind] . finditer('ll', text): print('ll found', m. pop() method removes and returns the last element from an existing list. Then use the dictionary to look up each item’s index location which is average time complexity O(1). Edit: I am using Apr 27, 2023 · Sometimes, while working with Python records, we can have a problem in which we need to perform grouping of elements of tuple by similar Kth index element. finditer to find all (non-overlapping) occurences: >>> import re >>> text = 'Allowed Hello Hollow' >>> for m in re. But I can't seem to find a way to do something similar in Python without having concat lists. a[2] Dec 5, 2012 · List comprehension is a shortcut to loop an element over list which after "in", and evaluate the element with expression, then return the result to a list, also you can add condition on which result you want to return >>> [expression(element) for **element** in **list** if condition ] This code does nothing but return all pairs that zipped up. This kind of problem can have application in web development domain. My apologies if missed some of the solutions, and I used my judgment to club similar answers. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. I thought of using itemgetter, but it does not work for multiple sets, for example labels=['C1','C Jan 9, 2021 · When accessing a list you give it an index i and it returns the i'th element: >>> x = [0,1,2,3,4,5,6,7] >>> print(x[3]) 3 Notice how when accessing the element "3" it will actually give the fourth element of the list. Jan 31, 2009 · If I want to delete elements at index 0 and 2, and try something like del somelist[0], followed by del somelist[2], the second Python List remove multiple items. You are again calling the first element of the first dimension of the array that has shape (3, 2). We can use an index() method or a simple for loop to accomplish this task. So I need to be able to do this without I do not exactly understand why you do not like . Which is easy to do - just use the built-in library function zip, as follows: for a_element, m_element in zip(a, m): s[a_element] = m_element Mar 13, 2018 · How can I efficiently find the matching index, using Python You can keep track of multiple (list1, list2): sorted_list1 = sorted((element, index) for index Dec 3, 2024 · Python uses zero-based indexing, meaning the first element is at index 0. Suppose: >>> idx = np. Let's discuss the certain way in which this task can be performed. searchsorted(A,B) For a generic case, when A & B are unsorted arrays, you can bring in the sorter option in np. – Jun 9, 2015 · finding index of multiple items in a list. index() throws an exception if the substring is not found. Dec 26, 2024 · In this article, we will explore various methods to remove multiple elements from a list in Python. Nov 17, 2021 · I want to select multiple groups of three or more elements from a list, according to some indices. This is: import numpy as np a1 = np. np. This is not a new answer, just an attempt to summarize the timings of all these methods. Learn how to find the index of multiple elements in a Python list using list comprehension, for loop, and NumPy with examples. my_list = [10, 20, 30, 40, 50] print(my_list[1:4]) [20, 30, 40] This example returns elements from index 1 to 3. searchsorted, like so - Aug 20, 2013 · I'm impressed with all the answers here. Sep 27, 2021 · I am currently making TicTacToe for a project using the turtle module. deque object. We use the inner index ([2]) to access an element within the selected sublist. For removing multiple elements from a list by index range we can use del operator. index('i', i_idx+1) // i_idx -> 16. So far, only this seems to work which looks hectic: Jul 3, 2012 · There wasn't much hint on performance for the different ways so I performed a test on removing 5000 items from 50000 in all 3 generally different approaches, and for me numpy was the winner (if you have elements that fit in numpy): Dec 21, 2024 · Python List Exercises, Practice and Solution: Write a Python program to access multiple elements at a specified index from a given list. 4. Jan 18, 2014 · As per the str. To retrieve multiple elements at once, use slicing. So you can pass the index which you got for the first item + 1, to get the next index. Jan 3, 2017 · list(animals[x] for x in (0,3)) is the subset you want. At that point, any single lookup is a constant-time operation. Use enumerate() to add indices to your loop instead: I have any array of values, that are often the same and I am trying to find the index of the smallest one. Python Full Co Jan 21, 2020 · item[0:5][8:13][17:21] this means to take a slice of item from index 0 to 4, which returns a new list of length 5 now take a slice from the returned list from index 8 to 12 which returns an empty list. remove but to get the first index corresponding to a value use . To find multiple elements of an element in the list, you can use the index() method multiple times by setting the start index to the previously found index. index(element) return index_element except ValueError: return None You can use np. pop(0) mylist. In the provided example, it prints the indices of 'apple' and 2. index(3) How to get index of item in deque. 1. test = 'Lorem Ipsum is simply dummy text of the printing and typesetting industry' i_idx = test. index(value) gets the first occurrence of value, and . I have tried to access the second Mar 26, 2020 · But removing an element from a list can change the indices of all elements in the list so the predefined indices do not point to the correct elements anymore. It is modifiable and changeable, unlike Tuples. Lists in Python are ordered. Oct 21, 2019 · Note that the reversal is needed (item_with_index[::-1]) because you want the items printed before the index but enumerate gives tuples with the index first. [GFGTABS] Python a = [10, 20, 30, 40, 50, 60, 70] # Elements to remove remov Oct 2, 2013 · If you can use numpy, you can do just that: >>> import numpy >>> the_list = numpy. e. randint(100, size=10) array([82, 9, 11, 94, 31, 87 Feb 21, 2018 · I tried using L. How come I can't index a Python list for multiple out-of-sequence index positions? mylist = ['apple','guitar','shirt'] It's easy enough to get one element, but not more than one. I then tried running a for loop over L and using L. May 23, 2016 · I was wondering if there was a way to insert multiple variables into a list at one time using the same index. what is the best way to get the index of element 3. In this article, we will see how to combine multiple lists into one list in Python. splice(insertIndex, removeNElements, insertThese). Learn Python from scratch with our Python Full Course Online , designed for beginners and advanced learners alike. Feb 23, 2023 · To Find the index of multiple elements in the Python list creates a dictionary containing the index location of each item in the list. While you may be using a style guide that doesn't explicitly forbid this practice, you can still make the comprehension more concise by doing something like the following: Nov 29, 2024 · This method is perfect for when you need to append multiple elements in a single operation. It’s rather simple – I have this list: [' Aug 26, 2022 · In this video, learn how to remove multiple elements from a List. all three elements of the first dimension) at column index 1 (where 0 and 1 represent the indexes for the two dimensions of the second dimension). l = ['a', 'b', 'c', 'd', 'e'] for items in l: print items[:3] The output should be: Jun 12, 2012 · Using np. Nov 28, 2024 · We have a sorted array with duplicate elements and we have to find the index of last duplicate element and print index of it and also print the duplicate element. pop() In Python 2, use xrange and pop only: Jan 17, 2015 · Is there a way to get array elements in one operation for known rows and columns of those elements? In each row I would like to access elements from col_start to col_end (each row has different starting and ending index). I need to choose some elements from the given list, knowing their index. Try Teams for free Explore Teams Oct 17, 2019 · I am writing test code in Appium of an Andriod Project in python . See full list on bobbyhadz. This is because counting array positions (lists in python) starts at zero in almost every programming language. If no index is provided, it will remove and return the last element by default. Feb 28, 2023 · Indexing in Python starts at 0, which means that the first element in a sequence has an index of 0, the second element has an index of 1, and so on. After you find each match, reset this parameter to the location just after the match that was found. Python List Index Multiple. Unlike numpy arrays, native Python lists do not accept lists as indices. Is there such a way? (There is already a Q&A about inserting single items, rather than multiple. for a continuous stretch of indexes read about slicing, for discontinued you could construct a new list containing only those indexes. Feb 20, 2014 · I'm trying to figure out how I can take a list of integers and return all the items in that list into another list as their max value, but with their index. data = "Welcome" del data[0] # TypeError: 'str' object doesn't support item deletion The best way is to reconstruct the string without the elements from the specific indexes and join them together, like this Nov 21, 2015 · import numpy as np a = [2, 4, 6, 8, , 1000] # total 500 elements b = np. Python Feb 27, 2023 · One way you can work around this type of problem is - Here we are inserting a list to the existing list by creating a variable new_values. To this end, I've tried the following codes: Dec 3, 2024 · We often need to find the position or index of an element in an array (or list). searchsorted, if you care about maintaining the order -. So deleting elements from it will not work. random. Oct 30, 2024 · Learn how to access elements at specific indexes in Python lists, with examples and best practices for beginners. find_elements_by_xpath(common_xpath) for element in forms: element. Let's explore some more methods and see how we index List of Lists In Python: %timeit response of all the answers listed above. May 12, 2016 · def fill_form(my_list): forms = driver. index(R[0]) every time, but similarly that only returns the first indices it finds at. index(sub[, start[, end]]) The second parameter is the starting index to search from. Remove multiple elements from a list using List Comprehension. Let's say I have a key with Mar 4, 2021 · Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand Some style guides, such as the Google Python Style Guide forbid using multiple for clauses in a list comprehension. Let's say I have the following HTML, which repeats multiple times i Jul 12, 2021 · For removing multiple elements from a list based on a certain condition, we can follow these approaches-Remove multiple elements from a list while Iterating. Share Improve this answer Feb 28, 2022 · In this tutorial, you’ll learn how to use the Python list index method to find the index (or indices) of an item in a list. In certain cases this can in fact be faster (but only some times). Apr 26, 2014 · Strings are immutable. The slice [start:end] returns a sublist from start to end-1. Basically how do I get 2 separate ranges within a list in Python. Modify each element in a list. Let’s delve into how you can retrieve multiple elements of a list knowing their indices, focusing on performance and method efficiency. Sounds like a one-liner Python is able to do! find index of element corresponding to another list. Related. I made a list with the coordinates on where the turtle should go based on the input given by the user. Monotonicity of an index can be tested with the is_monotonic_increasing() and is_monotonic_decreasing() attributes. Python. Note that we are inserting the values in the second index, i. new_list = [old_list[i] for i, e in enumerate(old_list) if i not in pos] This will work for both the list in your question by getting rid of the element at index specified by pos, just substitute old_list with list name you currently have: Given an array of integers, I need to find the indexes of many of its elements stored in a different array. Nov 20, 2015 · Question: I have two longs lists, ~50,000 elements in each, that are the exact same size. Number of elements is the same for each row, elements are consecutive. You can use it in the loop, but note that the str. Python a = [ 10 , 20 , 30 , 40 , 50 , 40 , 60 , 40 , 70 ] # Find the index of 40 between index positions 4 and 8 res = a . But I want to know all the objects that are the same. If it is found, that corresponding data is also displayed on the console. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. So if you have a value 1. Thus, this is the Python equivalent: showlist = [{'id':1, 'name':'Sesaeme Street'}, {'id':2, 'name':'Dora the Explorer'}] Sorting example: from operator import attrgetter showlist. send_keys(my_list[forms. Examples: Input : arr[] = {1, 5, 5, 6, 6, 7} Output : Last index: 4 Last duplicate item: 6 Inpu @Qbik Because in Python 2, it does not leak the loop variable as a new scope is created for the generator expression. 0) will always return 2, no matter how many times 1. I go through an Dec 8, 2024 · arr[-4:-1]: This slice selects elements starting from the fourth-to-last element (index -4) to the second-to-last element (index -1), returning [40, 50, 60]. The general idea: I have a list of event IDs. If no such element found print a message. index(1. This works well in Python 3: for x in range(2): mylist. Instead you want to call: print(a[0:3][:,1]) >>>[2 4 6] Which gives you all of the row elements (i. 3) You can use C arrays with the C API, using e. This method is particularly useful when we need to manipulate a list dynamically, as it directly modifies the original list. [GFGTABS] Python a = [10, 20, 30, 40, 50, 60, 70] # Elements to remove remov Sep 17, 2016 · In JavaScript, I can use splice to insert an array of multiple elements in to an array: myArray. pull a value at a specific index. Is there any way to return every index of same values in the list. end()) ll found 1 3 ll found 10 12 ll found 16 18 Aug 25, 2015 · There are a bunch of approaches for getting the index of multiple items at once mentioned in passing in answers to this related question: Is there a NumPy function to return the first index of something in an array?. However, for completeness, let me add another way of "removing" array elements using a boolean mask created with the help of np. Combine Multiple Lists Into One List PythonBelow are some of the ways by which we ca Feb 15, 2022 · you can only index by 1 index, for a list of indexes you need to get a list back. array([ 4, 5, 6, 1, 2 Find the minimum value, then iterate the list with index using enumerate to find the minimum values: >>> a = [2,4,5,2] >>> min_value = min(a) >>> [i for i, x in enumerate(a) if x == min_value] [0, 3] Mar 18, 2022 · How to Get Index of All Occurrences of Element in a Python List with a For Loop and Enumerate. The enumerate function is used to iterate over an object and returns both the index and Dec 2, 2018 · In this article, we will explore various methods to remove multiple elements from a list in Python. I considered the case of a series with 25 elements and assumed the general case where the index could contain any values and you want the index value corresponding to the search value which is towards the end of the series. Say we have a 1D data array and want to extract three portions of it like below: data_extractions = [] for start_index in range(0, 3): data_extractions. index() which will only find the first occurrence of your value in the list. x = [10, 20, 30, 40, 50] Using Slicing to Extract Multiple Elements. Python Simple. com Nov 15, 2024 · When you need to select specific items from a list by their indices in Python, several approaches can help you achieve this goal seamlessly. in1d(A,B))[0] You can also use np. index(value): ind=item_list. So for example, let's say we have a list of [a, b, c] and [0,1,2,3,4] and I wanted to Apr 14, 2017 · I'm looking for a way to select multiple slices from a numpy array at once. Example: Even if it's a late answer: I think this is still a very good question and IMHO Python (without additional libraries or toolkits like numpy) is still lacking a convenient method to access the indices of list elements according to a manually defined filter. nonzero(np. The problem is that I am not able to access two button in two different Activity having same Id . find_elements(By. This method creates a new array by combining the original array and the new elements. index) of the corresponding household (agent): # if element is found it returns index of element else returns None def find_element_in_list(element, list_element): try: index_element = list_element. The wide variety and creativity of the answers suggests there is no single best practice, so if your code above works and is easy Dec 1, 2018 · Assuming you have any old_list with a list of index pos that you want to get rid of:. Let say I would like to create a new list, which contains element with index 1, 2, 5, from given list [-2, 1, 5, 3, 8, 5, 6]. itemgetter seems to be the winner to me. mylist[0] returns 'apple', but mylist[0,2] returns TypeError: list indices must be integers or slices, not tuple. index(j)) return N Jun 22, 2020 · Due to list. sort(key=attrgetter('id')) BUT! With the example you provided, a simpler datastructure would be Oct 10, 2013 · Is there a simple way to index all elements of a list (or array, or whatever) except for a particular index? E. index ( 40 , 4 , 8 ) print ( res ) Oct 6, 2010 · Using regular expressions, you can use re. For example, if we have a string "Hello", we can access the first letter "H" using its index 0 by using the square bracket notation: string[0] . isin. Jun 26, 2018 · I just want to get those with the index that is a multiple of two code=[1,2,4,7,2,6,8] ncode=[code[i] for i%2==0] from list python, element with index multiple of Jun 26, 2020 · Though, there is a pitfall to this solution. Oct 30, 2024 · Accessing a Range of Elements. append(data[start_index: start_index + 5]) Afterwards data_extractions will be: I'm new to python and I was wondering if there's a way for me to pull a value at a specific index. remove(value) removes the first occurrence of value. Sort based on the element, ignoring the Oct 31, 2022 · #2: Get the indices of multiple list elements with Python We can use the same technique in order to print the indices of occurrences of multiple values in a list. Ask questions, find answers and collaborate at work with Stack Overflow for Teams. Changing all items in a list at once. enumerate provides this quite readily. A simple for loop can also be used to remove multiple elements from a list. Jan 15, 2010 · Is there some syntax that allows me to extract both the index (k) and the element (i) simultaneously using either a loop, list comprehension, or generator? The task is in scientific computing, so there is a lot of stuff in the loop body, making a list comprehension probably not powerful enough on its own, I think. str. The method replicates the behavior of the indexOf() method in many other languages, such as JavaScript. array(range(0,101,10)) >>> the_indices = [2,5,7] >>> the_subset = the_list[the Aug 19, 2015 · If you have a list in python, and want to extract elements at indices 1, 2 and 5 into a new list, how would you do this? This is how I did it, but I'm not very satisfied: >>> a [10, 11, I'd like to select multiple, non-adjacent ranges from a 1d numpy array (or vector). You need to wrap the generator expression in list to print it because it does not have an acceptable __str__ or __repr__ on its own. If I want the 1st, 2nd, 5th and 6th elements of a list I know I can do this, l = range(0,15) l[1:3]+l[5:7] but this assumes that l is easy to write. (f*** Lua) Oct 24, 2024 · The pop() method is used to remove an element from a list at a specified index and return that element. delete is the fastest way to do it, if we know the indices of the elements that we want to remove. We transform a and m into a list of pairs (element from a, element from m), and iterate over the pairs. In this example, below function `get_indices` takes a list of `lst` and a list of `targets`, returning the indices of the targets found in the original list. Being able to work with Python lists is an important skill for a Pythonista Feb 21, 2012 · The sorting done by Python is stable, meaning that you can in fact sort it twice, first on the least important element, then on the most important element. , mylist[3] will return the item in position 3 milist[~3] will return the whole l Feb 25, 2022 · elements = driver. What I did is: a = [-2,1,5,3,8,5,6] b = [1,2,5] c = [ a[i] for i in b] Is there any better way to do it? something like c = a[b] ? Feb 5, 2024 · Below, are the ways To Get Index Of Multiple List Elements In Python. Input : If the index of a Series or DataFrame is monotonically increasing or decreasing, then the bounds of a label-based slice can be outside the range of the index, much like slice indexing a normal Python list. element_class; id attributes can be shortened as #element_id; So precisely, your locator strategy can be: elements = driver. Dec 16, 2024 · Different techniques for accessing list elements in Python include indexing, list comprehension, slicing, and loops, each with varying efficiency and use cases. xbmdtco tacxe zye ycrdnu muka qwyjph zrhuls ecca glrs uzq