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) WebJul 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.
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WebJun 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. WebNov 1, 2011 · It turns out that, if the input array doesn't have duplicate elements, all methods are more or less equally fast, independently of whether the input data is a Python list or a NumPy array. If the input array is large, but contains just one unique element, then the set, dict and np.unique methods are costant-time if the input data is a list.
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 WebMar 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)
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 WebAug 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. …
WebHow 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)
WebNov 14, 2024 · Using generator expressions and comprehensions this is pretty straightforward. First let's get all values that appear more than once in a set. x = [1.2, 2.4, 3.1, 4.0, 5.6, 6.5, 1.2, 3.1, 8.1, 23.6, 29.3] multiples = set (a for a in set (x) if x.count (a) > 1) Now, to get the indexes, we can use enumerate and a list comprehension to only ... tangier restaurant cynthia georgeWebOct 7, 2008 · @stefanct this likely does double the complexity, I believe the in operator on a list has linear runtime. @ApproachingDarknessFish stated it would iterate twice which answers your question, and is right in saying that doubling the linear complexity is … tangier rent a carWebAug 17, 2024 · Example 3: Working of the index () With two Parameters only. In this example, we will see when we pass two arguments in the index function, the first argument is treated as the element to be searched and the second argument is the index from where the searching begins. list_name.index (element, start) Python3. list1 = [6, 8, 5, 6, 1, 2] tangier rental car drop off timeWebAug 26, 2024 · While working with Python list, sometimes, we require to check for duplicates and may also sometimes require to track their indices. This kind of … tangier scheduling physician log inWebMar 23, 2012 · Then it goes to the next element 31, with index 1, and checks if element 31 is present in the input_list[2:] (i.e., from index 2 till end of list), Because 31 is present in input_list[2:], it will return 31. similarly it goes through all the elements in the list, and will return only the repeated/duplicate elements into a list. tangier shootingtangier restaurant struthersWebApr 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 tangier public transport