Null Pointer Exception When Populating a ListView
What is a NullPointerException, and how do I fix it?
Using multiple wildcard parameters with arcpy.ListFeatureClasses I know there has to be a way to do this but I'm having trouble figuring out how to do so. I would like to create a list of feature classes to perform operations on however, I want to have the list contain feature classes which have 2 separate and distinct file name identifiers. The code would look something like:  FCS = arcpy.ListFeatureClasses("X_*" OR "*_Y")   I know OR is incorrect however, is there some way to do this without having to re write code to work with the second wildcard. Thanks for helping gout, i know there is a selection method in the Select By Attributes which allows for multiple wildcard use using the OR statement. bash: syntax error near unexpected token `}' A while back I read about the super Kamiokande detector detected a large neutrino flux and then several hours later a supernova was seen. Anyone know of this with sources? I don't recall the source at the moment. How to create dummy webcam? I would like to join some videoconference, but I don't own a webcam and the conference software requires one.  So my question is, can I create a dummy one? I don't care what the cam will cast, I just need to appear to have one. Objective-C: Use singleton vs. use class as an object? I'm using a 5 V / 2 A voltage regulator () without a heatsink. I'm testing the circuit with a microcontroller (PIC18FXXXX), a few LEDs and a 1 mA piezzo buzzer. The input voltage is aprox. 24 VDC. After running for a minute, the voltage regulator starts to overheat, meaning it burns my finger if I keep it there for more than a second. Within a few minutes it starts to smell like it's burnt. Is this a normal behavior for this regulator? What could cause it to heat that much?    Other components used in this circuit:  L1:   R2:   F1: Copyright of a set of colors? I often see color combinations on webpages, images, posters, products etc. that harmonize really well. Am I allowed to use those colors in my own design?   This is solely about the colors. I will not use images, logos or shapes from that source, and my content is not related to the original color source. I am also far from any commercial aspect here. How to prove wave nature of large object? Baking lots of bread - keeping a yeast starter What is the word for act of monotonously demanding for something (many be a toy) repeatedly? More than one private key for RSA In an RSA-encryption scenario, Bob's public key pair $(n, e)$ is $(143, 43)$. An attacker Mallory tries brute-force and comes to $d = 7$ as the private key. The value of $φ(143) = 120$ is not known to Mallory. However from $43 \cdot d \equiv 1 \bmod 120)$, one can calculate the first positive element $d = 67$ from multiplicative group $d = 120 + 67n$ and $n \in \mathbb{Z}$ $d = 7$ clearly doesn't fit in that multiplicative group, so how come it can successfully decrypt the encryption? How do I call one constructor from another in Java? Is it possible to call a constructor from another (within the same class, not from a subclass)? If yes how? And what could be the best way to call another constructor (if there are several ways to do it)? How to check if click event is already bound - JQuery Ignore .DS_Store and Icon files in a folder with Cocoa NSFIleManager Could you help me finding some less colloquial equivalent to highlighted phrases of this speech Today I want to be able to give you some good tips on parallel parking. It's part of your road test. It's something you need to learn. For most new drivers it's real difficult, because they're not able to judge angles. And parallel parking is all about angles. I'll take you through a typical parking, I'll take you through how I teach it , and maybe that'll help you in passing your road test. The first thing you want to do is you want to pull over over and you want to stop alongside a parked car. Typically, an inspector will give you a command to pull over, stop next to the red or blue car. You're just going to pull over, put your blinker on to the right, and pull over even with that car.     taken from a series of videos teaching driving   Why did the man use  be able in his speech? What is the difference between be able and I would like to or I want ? I mean what the listener should make of  I want to be able to give you ...  . Why did not he say I want to give you... ?  When he says I'll take you through a typical parking , I get the meaning of take one through ,It means I am going to teach you , isn't it? But my real concern is what the second I'll take you through means, while saying I'll take you through how I teach it . Perhaps it doesn't mean I will teach you that how I teach it ! , does it? The man always says the first thing you want to do . Why does not he say the first thing you should do , the first thing you need to do ? What are the diffrences in meaning? Isn't it unnatural saying you want to do ? In the last sentence he says You're just going to pull over, is the use of going to just weakening would and will? I think here it means something else. I think it means you just want to or you just start Answering beyond the question's scope Is answering beyond the scope of the question a valid thing? Or should we just stick to the question asked and ignore any potential bugs which might be present (of course OP is unaware of that, as of now).  To make myself more clear, please have a look at this .  There are 3 answers which talk about the issue asked and that's it. If you look at my answer, I've added an additional point about a potential bug which the OP has missed now (may find out later). So is it a good thing to point out such potential bugs or not? Should this practice be encouraged? Prove F test is equal to T test squared I need to show that F test is equal to T test squared, when the T test is for 2 independent groups and assuming variances are equal.  I know that $F=\frac{MSB}{MSW}=\frac{SSB/k-1}{SSW/N-K}$ and I know that $T=\frac{X-Y}{S_p \sqrt{\frac{1}{n}+\frac{1}{m}}}$,   so $T^2=\frac{(X-Y)^2}{S_p^2 ({\frac{1}{n}+\frac{1}{m}})}$  I've seen this proof in Regression but here we're not using MSE and MSR, so i'm not sure how to connect between the two. Aware abbreviating those commands need not always be helpful, I would like to know how to abbreviate them? The following is what I tried, which does not work:  \documentclass[11pt,handout]{beamer} \newcommand{\bframe}{\begin{frame}} \newcommand{\eframe}{\end{frame}} \newcommand{\ftitle}{\frametitle}   \author{Author} \title{Title}   \begin{document} \maketitle  \begin{frame} \frametitle{Outline}  \end{frame}   \bframe \ftitle{Introduction}  \eframe    \end{document}   At first I thought it might be the case that commands such as \bframe was already defined. But using \def instead still gives no desired result. Trying to find a Sci-Fi movie, probably from the 50's or 60's I’m trying to identify a movie I saw when I was very young.  It was a “Saturday Matinee” playing on one of the local stations, and I likely watched it in the late 60’s.  So I expect that the movie is from the 50’s or 60’s.  I watched it in black and white, but it could have been a color movie on a black and white set. I clearly recall a scene where scientists enter a lab and some see something move past them in a blur.  Later in the movie, they come upon themselves in the same lab where they appear to be frozen and not moving.  Then they notice that their “other selves” are moving, just almost inperceptibly slowly.  They are encountering themselves but at a completely different time scale. Unfortunately, I don’t recall much else about the movie, just the idea that they encounter themselves once with the others flashing past, and again seemingly not moving at all.  If this rings any bells with anyone, I’d love some pointers to try to track this movie down. Is it legal/well-defined C++ to call a non-static method that doesn't access members through a null pointer?