Understanding lambda's sort function in python -

-

i trying sort list of lists in python. have written following code:

def sort(intervals):     if intervals == [] : return []       intervals.sort(key = lambda x:x.start)     return intervals  = [[1,3],[8,10],[15,18],[2,6]] print(sort(a))

i getting following error:

attributeerror: 'list' object has no attribute 'start'

please can explain lambda function sort , details above error. thank you!!

the reason error message sorting based on attribute not list (start not attribute of list'), quick fix is, either use sort method of list or use built-in method sorted:

1 - using sort method of list:

intervals.sort(key = lambda l:l[0])

2 - using built-in method sorted:

intervals = sorted(intervals, key=lambda l:l[0])

reading more sorting list in wiki post, interesting.


Comments

Post a Comment

Popular posts from this blog

java - HTTP Status 500 - An exception occurred processing JSP page /second.jsp at line 15 -

-
this question has answer here: what nullpointerexception, , how fix it? 12 answers i have 4 pages on jsp web project student showing details db.. have used tomcat web server. index.html <body> <h1> student search page</h1> <form action="second.jsp"> <h2> enter id search details</h2> <input type=text name=id1 /> <br/> <input type=submit value=search /> </form> </body> second.jsp <body> <% string id =(request.getparameter("id1")); studentdao std=new studentdao(); student s=std.searchinfo("id"); %> <h1> <%=s.showstudent()%></h1> </body> student.java import java.io.*; public class student implements serializable { string name; string id1,phone,clas; ...
Read more

SQL Server - MyCTE query based on 24 hour period (next day) -

-
i have bit of code: ;with mycte ( select *, row_number() over(partition carduser order cardtableid) newvariation cardchecker ) update mycte set status = newvariation which updates status column, want happen on 24 hour period, status starts again next day @ 1, , counts again based on carduser specified above: current data , happens: 2 aaa 1 2015-06-25 08:00:00.000 123 1 null 3 ccc 1 2015-06-25 00:00:00.000 124 1 null 4 aaa 1 2015-06-25 17:30:00.000 125 2 null 5 aaa 1 2015-06-26 17:30:00.000 125 *3* null what want happen: 2 aaa 1 2015-06-25 08:00:00.000 123 1 null 3 ccc 1 2015-06-25 00:00:00.000 124 1 null 4 aaa 1 2015-06-25 17:30:00.000 125 2 null 5 aaa 1 2015-06-26 17:30:00.000 125 *1* null im not quite sure how add above query possible point me in right direction? the main problem eventtime field contains both date , time, adding partition means status 1 based on time parameter of field thanks ...
Read more

php - Using str_replace to translate a MySQL Table in html -

-
i have website contains pricelist of cs:go items. now, how did this: mysql db w/ prices --> select db x ( item name ) --> echo table ( works fine ) now want translation of item names. how planned it: mysql db --> $result= ( signature character ) --> $translate = str_replace (signature character $result) however, there's issue code or str_replace think. $translate returns $result no filtering. <?php require 'lang.php'; $servername = "localhost"; $username = ""; $dbname = ""; $password = ""; // create connection $conn = new mysqli($servername, $username, $password, $dbname); // check connection if ($conn->connect_error) { die("connection failed: " . $conn->connect_error); } // filter name $sql = "select name, price utf name 'k%'"; $result = $conn->query($sql); // translate $tr = str_replace('k','karambit','$result'); // ech...
Read more