duplicates

问题 I am new to r and I have problems with removing duplicated characters. Here is my code: library(RCurl) x <- getURL("https://raw.githubusercontent.com/eparker12/nCoV_tracker/master/input_data/coronavirus.csv") y <- read.csv(text = x) z <- duplicated(y$jhuID) I tried something like z <- ... but it did not work. For the column jhuID in the dataframe it is the class character but there are many name of countries that repeat multiple times and my goal is to delete those duplicated name of country

问题 This question already has answers here : LINQ's Distinct() on a particular property (21 answers) Closed 4 years ago . I want to remove the duplicates based on a property of my object: public class MyType { public string _prop1; public string _prop2; public LocationsClass(string prop1, string prop2) { _prop1= prop1; _prop2= prop2; } } ... List<MyType> myList; So basically I want to remove all MyType objects from myList, with the same value in _prop1. Is there a way to do this, probably with

问题 This question already has answers here : LINQ's Distinct() on a particular property (21 answers) Closed 4 years ago . I want to remove the duplicates based on a property of my object: public class MyType { public string _prop1; public string _prop2; public LocationsClass(string prop1, string prop2) { _prop1= prop1; _prop2= prop2; } } ... List<MyType> myList; So basically I want to remove all MyType objects from myList, with the same value in _prop1. Is there a way to do this, probably with

问题 Is there a simple way to retrieve a list of all unique values in a column, along with how many times that value appeared? Example dataset: A A A B B C ... Would return: A | 3 B | 2 C | 1 回答1: Use GROUP BY: select value, count(*) from table group by value Use HAVING to further reduce the results, e.g. only values that occur more than 3 times: select value, count(*) from table group by value having count(*) > 3 回答2: SELECT id,COUNT(*) FROM file GROUP BY id 来源： https://stackoverflow.com

问题 For school i am writing a small program for a rankinglist for a game. I am using dicts for this, with the name of the player as keyname, and the score as keyvalue. there will be 10 games, and each game will have an automatic ranking system which i print to file. ive already managed to code the ranking system, but now im facing a bigger challange which i cannot solve: I have to make an overall ranking, which means someplayername can be in several contests with several scores, but i need to

问题 For school i am writing a small program for a rankinglist for a game. I am using dicts for this, with the name of the player as keyname, and the score as keyvalue. there will be 10 games, and each game will have an automatic ranking system which i print to file. ive already managed to code the ranking system, but now im facing a bigger challange which i cannot solve: I have to make an overall ranking, which means someplayername can be in several contests with several scores, but i need to

问题 For school i am writing a small program for a rankinglist for a game. I am using dicts for this, with the name of the player as keyname, and the score as keyvalue. there will be 10 games, and each game will have an automatic ranking system which i print to file. ive already managed to code the ranking system, but now im facing a bigger challange which i cannot solve: I have to make an overall ranking, which means someplayername can be in several contests with several scores, but i need to

问题 This question already has answers here : python count duplicate in list (6 answers) Closed 2 years ago . I am trying to construct this function but I can't work out how to stop the function counting the same duplicate more than once. Can someone help me please? def count_duplicates(seq): '''takes as argument a sequence and returns the number of duplicate elements''' fir = 0 sec = 1 count = 0 while fir < len(seq): while sec < len(seq): if seq[fir] == seq[sec]: count = count + 1 sec = sec + 1

问题 After joining two dataframes (which have their own ID's) I have some duplicates (repeated ID's from both sources) I want to drop all rows that are duplicates on either ID (so not retain a single occurrence of a duplicate) I can group by the first ID, do a count and filter for count ==1, then repeat that for the second ID, then inner join these outputs back to the original joined dataframe - but this feels a bit long. Is there a simpler method like dropDuplicates() but where none of the

问题 After joining two dataframes (which have their own ID's) I have some duplicates (repeated ID's from both sources) I want to drop all rows that are duplicates on either ID (so not retain a single occurrence of a duplicate) I can group by the first ID, do a count and filter for count ==1, then repeat that for the second ID, then inner join these outputs back to the original joined dataframe - but this feels a bit long. Is there a simpler method like dropDuplicates() but where none of the