duplicates

问题 This might not be very sensible, but I'ld like to let MySQL return me the exact duplicate rows if there are duplicate criteria in the WHERE IN clause. Is this possible? Take this example: SELECT columns FROM table WHERE id IN( 1, 2, 3, 4, 5, 1, 2, 5, 5) I'ld like MySQL to return me rows with id 5 three times, id's 1 and 2 twice, and 3 and 4 once. As the lenght of the IN arguments, as well as the duplicate count (once, twice, three times, etc.), will be arbitrary I don't want to rely on UNION

问题 I'm developing a single serving site in PHP that simply displays messages that are posted by visitors (ideally surrounding the topic of the website). Anyone can post up to three messages an hour. Since the website will only be one page, I'd like to control the vertical length of each message. However, I do want to at least partially preserve line breaks in the original message. A compromise would be to allow for two line breaks, but if there are more than two, then replace them with a total

问题 I have a data frame that looks like this: Chr start stop ref alt Hom/het ID chr1 5179574 5183384 ref Del Het 719 chr1 5179574 5184738 ref Del Het 915 chr1 5179574 5184738 ref Del Het 951 chr1 5336806 5358384 ref Del Het 376 chr1 5347979 5358384 ref Del Het 228 I would like to merge any duplicate rows, combining the last ID column so that all IDs are in one row/column, like this: Chr start stop ref alt Hom/het ID chr1 5179574 5183384 ref Del Het 719 chr1 5179574 5184738 ref Del Het 915, 951

问题 I have a list of pairs: [0, 1], [0, 4], [1, 0], [1, 4], [4, 0], [4, 1] and I want to remove any duplicates where [a,b] == [b,a] So we end up with just [0, 1], [0, 4], [1, 4] I can do an inner & outer loop checking for the reverse pair and append to a list if that's not the case, but I'm sure there's a more Pythonic way of achieving the same results. 回答1: If you need to preserve the order of the elements in the list then, you can use a the sorted function and set comprehension with map like

问题 I have the following data: x1 x2 x3 x4 34 14 45 53 2 8 18 17 34 14 45 20 19 78 21 48 2 8 18 5 In rows 1 and 3; and 2 and 5 the values for columns X1;X2,X3 are equal. How can I output only those 4 rows, with equal numbers? The output should be in the following format: x1 x2 x3 x4 34 14 45 53 34 14 45 20 2 8 18 17 2 8 18 5 Please, ask me questions if something unclear. ADDITIONAL QUESTION: in the output x1 x2 x3 x4 34 14 45 53 34 14 45 20 2 8 18 17 2 8 18 5 find the sum of values in last column

问题 I have two flat lists where one of them contains duplicate values. For example, array1 = [1,4,4,7,10,10,10,15,16,17,18,20] array2 = [4,6,7,8,9,10] I need to find values in array1 that are also in array2, KEEPING THE DUPLICATES in array1. Desired outcome will be result = [4,4,7,10,10,10] I want to avoid loops as actual arrays will contain over millions of values. I have tried various set and intersect combinations, but just couldn't keep the duplicates.. Any help will be greatly appreciated!

问题 After some issues with our hosting, we decided to move our Git repository to GitHub. So I cloned the repository and tried pushing that to GitHub. However, I stumbled upon some errors we have never encountered before: C:\repositories\appName [master]> git push -u origin master Counting objects: 54483, done. Delta compression using up to 2 threads. Compressing objects: 100% (18430/18430), done. error: object 9eac1e639bbf890f4d1d52e04c32d72d5c29082e:contains duplicate file entries fatal: Error

问题 I am building java jar file using ant. I need to include additional jars using "zipfileset src="xxx.jar" "zipfileset src="yyy.jar" and both xxx.jar and yyy.jar have the classes with the SAME fully-qualified class names. So the resulting jar file has duplicate class names. What are the possible implications of having duplicates? Thank you. 回答1: If they're duplicate implementations, nothing–it wouldn't matter which is loaded. If not, you're at the mercy of class load order, and may get a

问题 I wrote this code in C++ as part of a uni task where I need to ensure that there are no duplicates within an array: // Check for duplicate numbers in user inputted data int i; // Need to declare i here so that it can be accessed by the 'inner' loop that starts on line 21 for(i = 0;i < 6; i++) { // Check each other number in the array for(int j = i; j < 6; j++) { // Check the rest of the numbers if(j != i) { // Makes sure don't check number against itself if(userNumbers[i] == userNumbers[j]) {

问题 I have a dataframe which contains duplicates values according to two columns (A and B): A B C 1 2 1 1 2 4 2 7 1 3 4 0 3 4 8 I want to remove duplicates keeping the row with max value in column C. This would lead to: A B C 1 2 4 2 7 1 3 4 8 I cannot figure out how to do that. Should I use drop_duplicates() , something else? 回答1: You can do it using group by: c_maxes = df.groupby(['A', 'B']).C.transform(max) df = df.loc[df.C == c_maxes] c_maxes is a Series of the maximum values of C in each