Get index of repeated elements in list python
WebWith most optimize way with respect to time and space complexity: Step-1: Start travelling the original array from last, Step-2: Once you find the given element. Step-3: Return the index = l - i -1; where l = total length of the array, i = index of the element in step-2. – ArunDhwaj IIITH. Sep 4, 2024 at 17:37. WebJun 15, 2014 · How do I repeat each element of a list n times and form a new list? For example: x = [1,2,3,4] n = 3 x1 = [1,1,1,2,2,2,3,3,3,4,4,4] x * n doesn't work for i in x [i]: x1 = n * x [i] There must be a simple and smart way. python Share Improve this question Follow edited Nov 12, 2024 at 11:01 johan 1,624 2 13 30 asked Jun 14, 2014 at 23:06
Get index of repeated elements in list python
Did you know?
WebOct 12, 2024 · How can I find all the indexes of a recurring item? For Example: list = ['A', 'A', 'B', 'A', 'B', 'B', 'A'] I want to return all occurrences of 'B', so it'd return: indexes = [2, 4, 5] python python-3.x list Share Improve this question Follow edited Apr 18, 2024 at 15:56 Tomerikoo 17.9k 16 45 60 asked Oct 12, 2024 at 5:22 desiigner 79 1 3 10 1 WebApr 25, 2015 · You can use the count () method from the list object to get a count equal to 1: >>> A= [1, 2, 3, 2, 5, 1] >>> unique= [i for i in A if A.count (i)==1] >>> unique [3, 5] Alternatively the Counter () class from the collections module can be used: A = [1, 2, 3, 2, 5, 1] c = Counter (A) print [key for key, count in c.iteritems () if count==1] Share
WebJan 3, 2016 · Use enumerate to keep track of the index and a set to keep track of element seen: l = [1, 1, 2, 3] inds = [] seen = set () for i, ele in enumerate (l): if ele not in seen: inds.append (i) seen.add (ele) If you want both: inds = [] seen = set () for i, ele in enumerate (l): if ele not in seen: inds.append ( (i,ele)) seen.add (ele) WebDec 16, 2024 · There are much more efficient ways of finding duplicates in list in python (yours is O(n^2)), and its probably just better using numpy library to do it: import numpy …
WebJan 18, 2014 · As per the str.index docs, signature looks like this. str.index(sub[, start[, end]]) The second parameter is the starting index to search from. So you can pass the index which you got for the first item + 1, to get the next index. WebApr 23, 2014 · Using a dictionary to count the items in a list (8 answers) Closed 6 months ago. I am new to Python. I am trying to find a simple way of getting a count of the number of elements repeated in a list e.g. MyList = ["a", "b", "a", "c", "c", "a", "c"] Output: a: 3 b: 1 c: 3 python python-2.7 Share Follow edited Feb 24, 2024 at 8:01 galoget 712 9 15
WebDec 17, 2024 · Python is a great language for doing data analysis, primarily because of the fantastic ecosystem of data-centric python packages. Pandas is one of those packages and makes importing and analyzing data much easier.. Pandas Index.get_duplicates() function extract duplicated index elements. This function returns a sorted list of index elements …
WebApr 8, 2024 · Find indexes of consecutive items in lists. and return a 2d list with the indexes of the repeating values: new_list = [] i = 0 while i < len (x)-1: if x [i] == x [i+1]: new_list.append ( [x [i],x [i+1]] i += 1. x is not necessarily sorted but has at least one series of repeating values. For example x can also be: high waisted blue jean shorts tank topWebMar 31, 2024 · This program uses the numpy library to convert a given list into an array, finds the indices of the given value in the array, and converts the resulting numpy array back to a list. Finally, it prints the list of indices. Python3 import numpy as np test_list = [1, 3, 4, 3, 6, 7] test_array = np.array (test_list) how many fancy goldfish in a 29 gallon tankWebJul 11, 2024 · Teams. Q&A for work. Connect and share knowledge within a single location that is structured and easy to search. Learn more about Teams high waisted blue jean flared pantsWebHow to count the number of repeated items in a list in Python - Python programming example code - Python programming tutorial - Actionable Python programming code. Data Hacks. Menu. Home; R Programming; ... Accessing Last Element Index of pandas DataFrame in Python (4 Examples) high waisted blue skirt longWebJun 9, 2011 · You can use a list comprehension with enumerate: indices = [i for i, x in enumerate (my_list) if x == "whatever"] The iterator enumerate (my_list) yields pairs (index, item) for each item in the list. Using i, x as loop variable target unpacks these pairs into the index i and the list item x. how many fangirls does william afton haveWebAug 22, 2024 · How do I get the index of a duplicated string in a list? Traversing through the length of the list so that we can keep a track of each index and print the index. … how many fan leaves to removeWebJul 31, 2011 · last_occurence=len(yourlist)-yourlist[::-1].index(element)-1 just easy as that.no need to import or create a function. Share. Improve this answer. Follow answered Apr 13, 2024 at 10:09. Prabu M ... Find last index of element in list with duplicate elements python. 0. index() of last occurrence in list in python. 0. how many fangs do spiders have