Use the rowid pseudocolumn. DELETE FROM your_table WHERE rowid not in (SELECT MIN(rowid) FROM your_table GROUP BY column1, column2, column3); Where column1, column2, and column3 make up the identifying key for each record. You might list all your columns.
Try this regular expression: \b(\w+)\s+\1\b Here \b is a word boundary and \1 references the captured match of the first group. Regex101 example here
I would suggest using the duplicated method on the Pandas Index itself: df3 = df3[~df3.index.duplicated(keep=’first’)] While all the other methods work, .drop_duplicates is by far the least performant for the provided example. Furthermore, while the groupby method is only slightly less performant, I find the duplicated method to be more readable. Using the sample data … Read more
You could possibly use a LINQ query to do this: int[] s = { 1, 2, 3, 3, 4}; int[] q = s.Distinct().ToArray();
>>> L = [1,1,1,1,1,1,2,3,4,4,5,1,2] >>> from itertools import groupby >>> [key for key, _group in groupby(L)] [1, 2, 3, 4, 5, 1, 2] For the second part >>> [k for k, g in groupby(L) if len(list(g)) < 2] [2, 3, 5, 1, 2] If you don’t want to create the temporary list just to take … Read more
I agree with R. Pate and Todd Gardner; a std::set might be a good idea here. Even if you’re stuck using vectors, if you have enough duplicates, you might be better off creating a set to do the dirty work. Let’s compare three approaches: Just using vector, sort + unique sort( vec.begin(), vec.end() ); vec.erase( … Read more
Remove duplicates from a List in C#
This will extract the rows which appear only once (assuming your data frame is named df): df[!(duplicated(df) | duplicated(df, fromLast = TRUE)), ] How it works: The function duplicated tests whether a line appears at least for the second time starting at line one. If the argument fromLast = TRUE is used, the function starts … Read more
Suppose you have a table employee, with the following columns: employee (first_name, last_name, start_date) In order to delete the rows with a duplicate first_name column: delete from employee using employee, employee e1 where employee.id > e1.id and employee.first_name = e1.first_name
There are at least 6 (!) ways to clone an array: loop slice Array.from() concat spread operator (FASTEST) map A.map(function(e){return e;}); There has been a huuuge BENCHMARKS thread, providing following information: for blink browsers slice() is the fastest method, concat() is a bit slower, and while loop is 2.4x slower. for other browsers while loop … Read more