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Automatic garbage collection is one of the important features of Python. Garbage collector mechanism attempts to reclaim memory occupied by objects that are no longer in use by the program.Python uses reference counting mechanism for garbage collection. Python interpreter keeps count of number of times an object is referenced by other objects. When references to an object are removed, the count for an object is decremented. When the reference count becomes zero, the object memory is reclaimed.Normally this mechanism is performed automatically. However, it can be done on purpose if a certain situation arises in the program. The 'gc' module ... Read More
If you want to select a single row on the basis of primary key, use the WHERE clause. The syntax is as follows −SELECT * FROM yourTableName WHERE yourPrimaryKeyColumnName = someValue;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table selectWithPrimaryKey -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Name varchar(20), -> Age int, -> Marks int, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.78 sec)Insert some records in the table using insert command. The query is ... Read More
Earlier, it was tough that the person who works remotely cannot socialize at all! Neither would his network be broad. It would actually be in the limited domain. However, a person who does not work as a permanent employee does not mean can not have a wide network of acquaintance. He too can have a lot of connections if he takes care of the followings:Make Less But Real RelationshipIn a remote working situation, the interactions require greater effort than the employees who are not the virtual employees. In such circumstances, it is important to make real and genuine relationships. This ... Read More
In MySQL, you can use two different types of quotation marks which is backtick and another is single quotes or double quotes. In this case, maybe you are using single quotes to the column name that’s why you are getting error. You need to use the backtick symbol (` `) instead of single quotes. Backtick can be used with column names while single quotes can be used for strings.To understand the above error, let us create a table. The query to create a table is as follows −mysql> create table Backtick_SymbolDemo -> ( -> Id int NOT NULL ... Read More
The “kk” format in Java Date is used to format hour in 01-24 format. Use SimpleDateFormat("kk") to get the same format.// displaying hour in kk format SimpleDateFormat simpleformat = new SimpleDateFormat("kk"); String strHour = simpleformat.format(new Date()); System.out.println("Hour in kk format = "+strHour);Above, we have used the SimpleDateFormat class, therefore the following package is imported −import java.text.SimpleDateFormat;The following is an example −Example Live Demoimport java.text.Format; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Calendar; public class Demo { public static void main(String[] args) throws Exception { // displaying current date and time ... Read More
Select an empty result set with the help of dummy table ‘dual’ from MySQL. The query is as follows −mysql> select 1 from dual where false; Empty set (0.00 sec)In the above query, “dual” is a dummy table and the above condition false. Therefore, it returns empty set.Let us check with true condition. It will return the selected value. The query is as follows −mysql> select 1 from dual where true;The following is the output −+---+ | 1 | +---+ | 1 | +---+ 1 row in set (0.00 sec)
The ModuleFinder class in 'modulefinder' module can determine set of modules imported by a certain script. This module has a command line interface as well as programmatic interface.For demonstration of functionality, use following script#modfinder.py import hello try: import trianglebrowser import nomodule, mymodule except ImportError: passCommand line interfaceFollowing command displays list of modules located as well as not found.E:\python37>python -m modulefinder modfinder.pyOutputName File ---- ---- m __main__ modfinder.py m hello hello.py m math m trianglebrowser trianglebrowser.py Missing modules: ? mymodule imported from __main__ ? nomodule imported from __main__Programmatic interfaceModuleFinder class in ... Read More
You can use date_format() to convert varchar to date. The syntax is as follows −SELECT DATE_FORMAT(STR_TO_DATE(yourColumnName, 'yourFormatSpecifier'), 'yourDateFormatSpecifier') as anyVariableName from yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table VarcharToDate -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Created_Time varchar(100), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (1.10 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into VarcharToDate(Created_Time) values('12/1/2016'); Query OK, 1 row affected (0.14 sec) mysql> insert ... Read More
To run SQL script in MySQL, use the MySQL workbench. First, you need to open MySQL workbench.The snapshot is as follows −Now, File -> Open SQL Script to open the SQL script.Alternatively, use the following shortcut key −Ctrl+Shift+OAfter that an option would be visible for you to choose your .sql file from the disk. In my system, the file is located on the Desktop. I will select the same “tblstudent” SQL file as shown in the following screenshot −After browsing .sql files, you need to select the option “Reconnect to database” as shown in the following screenshot −Now, it will ... Read More
The “K” format in Java Date is used to display hour in 0-11 in AM/PM format. Use SimpleDateFormat("K") to get the same format.// displaying hour in K format SimpleDateFormat simpleformat = new SimpleDateFormat("K"); String strHour = simpleformat.format(new Date()); System.out.println("Hour in K format = "+strHour);Above, we have used the SimpleDateFormat class, therefore the following package is imported −import java.text.SimpleDateFormat;The following is an example −Example Live Demoimport java.text.Format; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Calendar; public class Demo { public static void main(String[] args) throws Exception { // displaying current date and time ... Read More