variables

问题 I have a small piece of code, which was working fine, until I decided to create a class and put things into that class. Now my problem is, I cannot change stringvariable anymore. Here is my code: import tkinter as tk import tkinter.ttk as ttk class MainApplication(tk.Frame): def __init__(self, parent, *args, **kwargs): tk.Frame.__init__(self, parent, *args, **kwargs) self.parent = parent frame1 = ttk.LabelFrame(root, text="PANEL A", borderwidth=5) frame1.grid(row=0, column=0, padx=5, pady=5)

问题 I am trying to eject my CDRom Drive at the click of a button. This works when the CDRom drive letter is hardcoded, but I am wanting to do it without hardcoding the CDRom Drive. If I find the CDRom drive on my computer and save it to 'TCHAR drive_letter', how can I pull that in to the code below? For some reason, it does not allow me to do 'EjectCdTray(drive_letter);'. The code is shown below: #include <tchar.h> #include <windows.h> #include <mmsystem.h> // for MCI functions // Link to winmm

问题 I have a variable and I want my user to be able to change this variable. The original value of the variable should change, so it can be also be used in another function. (The user enters a new date, and this variable then gets changed at the end of the url (of the other function, that calls the map), which then shows the data from that date.) I know I have to make my variable global, but I still doesn't work. It's probably something dumb, but I just can't seem to make it work. What am I doing

问题 To have some exercise in learning Python, and especially with Object orientated programming. I'm creating a simple text based game. I'm a bit struggling with the use of global variables. People say it's better to avoid them. My question how can I make thing work without them and where to declare those variables. Currently in my main() method I'll start the game based on Classes for every room or interaction that can happen in the game. But there are some objects I want to access anytime, like

问题 I'm looking to use a variable as part of an XPath expression. My problem might be the msxsl node-set function... not sure. But don't let that cloud your judgement... read on... I'm using a .NET function to load up the content file, which is passed in via bespoke XML content. The @file results in an XML file. The bespoke XML the sits on the page looks like : <control name="import" file="information.xml" node="r:container/r:group[@id='set01']/r:item[1]" /> The XSL looks like : <xsl:variable

问题 I've been trying to turn the output of the following two commands into variables, so that I can use them in a batch file, however I'm not having any luck: WMIC /namespace:\\root\SecurityCenter2 PATH AntiVirusProduct WHERE (displayName="Emsisoft Anti-Malware" or displayName="Emsisoft Internet Security") GET displayName /value WMIC /namespace:\\root\SecurityCenter2 PATH AntiVirusProduct WHERE (displayName="Emsisoft Anti-Malware" or displayName="Emsisoft Internet Security") GET

问题 I have scenario like this public class Test{ static int a; int b; public static void main(String[] args){ Test t1 = new Test(); Test t2 = new Test(); } } What will be the variables in object t1 and object t2? As per my understanding since variable a is a static variable it will be both in object 1 and object 2. And b will be created separate copy for both the objects. But when I assign a value to variable b ie( int b=1 ) and call it like System.out.println(t1.b) , System.out.println(t2.b)

问题 I have scenario like this public class Test{ static int a; int b; public static void main(String[] args){ Test t1 = new Test(); Test t2 = new Test(); } } What will be the variables in object t1 and object t2? As per my understanding since variable a is a static variable it will be both in object 1 and object 2. And b will be created separate copy for both the objects. But when I assign a value to variable b ie( int b=1 ) and call it like System.out.println(t1.b) , System.out.println(t2.b)

问题 I am using below syntax to declare and use variable in hive sql query. But it gives me an error as below SET aa='10'; SELECT col1 as data, ${aa} as myVar from myTable; ERROR: org.apache.hive.service.cli.HiveSQLException: Error while processing statement: Cannot modify aa at runtime. It is not in list of params that are allowed to be modified at runtime I have also tried using hiveconf SELECT ${hiveconf:aa} from myTable; 回答1: You can not pass variable like that. You need to use --hivevar . You

问题 I use an excel file in which I determine the names of sensor, and a formula allowing me to create a new "synthetic" sensor based on real sensors. I would like to write the formula as string like for example "y1 + y2 + y3" and not "df ['y1'] + df ['y2'] + df ['y3]" but I don't see which method to use? Excel file example: My script must therefore create a new sensor for each line of this excel file. This new sensor will then be uploaded to my database. The number of sensors to calculate the new