Take the list variable num1 = [] and say i also take num1_child = randint(0,100) how do I go about making num1 progressively become a longer list by adding num1_child to the list, as opposed to simply changing it's value every eteration? (I looked at:  but did not fully understand how to implement that in my code)
What's the difference between the list methods append() and extend()?
I've looked at the demo of Beeline reader and would like to test it out on a physical version of my books, which are done in LaTeX. I'm wondering if it would even be possible.   Beeline reader takes online test a puts a slight gradient on the letters for a single line of text. On the next line it reverses the direction of the gradient. The idea being that it helps tracking text and improves speed of reading.  Any hints or suggestions as to how to do this in LaTeX?  What follows is an example taken from "[" as first character in table row Whenever I try to compile a table that has a "[" as first character in a row it gives me the error:  Missing number, treated as zero. Illegal unit of measure   Example:  \begin{table}[htb]     \centering     \begin{tabular}{r|r}         [some text ] &amp; ... \\         [some more text ] &amp; ...     \end{tabular}     \caption{...}     \label{tab:...} \end{table}   How can I print "[" as first character in a row? Why is the $(\frac{1}{2},\frac{1}{2})$ representation of the Lorentz group realized as the vector space of Hermitian $2\times 2$ matrices? How to setup Squid Proxy (for localhost services and Tor and I2P) What is the difference between linear equation and linear regression? I am using linear equation to find the correlation of values of x, y and z  3x + 4y + 2z = 6 4x + 1y + 4z = 17 8x + 2y + 5z = 9   I would like to know the difference between linear equation and linear regression. Is it the same in approach? Prove existence of disjoint open sets containing disjoint closed sets in a topology induced by a metric. Why are there directories called Local, LocalLow, and Roaming under \Users\\AppData? I have a workstation running Windows Server 2008 that's logged into an  domain, and I have a dual boot with Ubuntu Linux. When running Linux, I'd like to be able to use the same Thunderbird profile I use under Windows, so I pointed Thunderbird to use a profile I found under:  \Users\(myname)\AppData\Local\Thunderbird\Profiles   It turns out it was not the correct profile -- it had the right configuration, but the Inbox was an old version. I eventually found out the correct path was:  \Users\(myname)\AppData\Roaming\Thunderbird\Profiles   What's the rationale behind those different places to store application data? AutoHotKey: Calling one script from another script How Can I Concatenate Column A and Column B into Column C in Excel? Column A has first name.  Column B has last name.  I need column C to be "display name" (first name and last name separated by a space).  I assume this involves the concatenate function.  Bonus Question: Column D is email address.  I need column E to be "username" (everything in email address left of the @ symbol).  I assume this involves some regular expression function. Vertical alignment in table: m-column, row size - problem in last column Let L1 be the line passing through the point $P_1=(−11, 10, −1)$ with direction vector $\vec d_1=\begin{bmatrix}−2\\ 3\\ −1\end{bmatrix}t$, and let $L_2$ be the line passing through the point $P_2=(−8, 9, 10)$ with direction vector $\vec d_2=\begin{bmatrix}−1\\ 3\\1\end{bmatrix}t$. Find the shortest distance, $d$, between these two lines, and find a point $Q_1$ on $L_1$ and a point $Q_2$ on $L_2$ so that $d(Q_1,Q_2) = d$.   I dont really understand how to properly approach this question, how do i start? Can a hotel kick you out if you let an unregistered guest share a room with you? We are going to an event and because of this event all hotels are fully booked. Now a friend wants to join us, but can't find accommodation. We are okay with him crashing in our hotel room, either on the couch or on a self-inflatable mattress. We have done this in the past where we secretly sneaked the "guest" in.   It is not that we don't want to pay the tourist tax, it is that when ask and the hotel says no, we can't sneak him in, because we drew attention to ourself. In many hotels you can just order another bed, but there are also a lot that don't have that service.   I don't have any ethical problems with my behavior of secretly hosting a guest. I did pay for the room. I don't like being sneaky about it, since again I do pay for the hotel room. Also if I have to choose between sneaking someone in the room to crash on the couch or let him/her sleep on bench in the park. I opt for the first.   Am I just worrying to much and will being honest about it in the end be acceptable to most if not all hotels? How do properties work in Object Oriented MATLAB? optexp environment error when compiling with XeLaTeX I have troubles with optexp environment. There is a code  \documentclass[pstricks,margin=12pt]{standalone}  \usepackage{pst-optexp}  \begin{document} \begin{pspicture}(3.2,5) \pnodes(0,3){A}(1,3){BS}(3,3){M1}(1,5){M2}(1,1){PD} \psset{mirrortype=extended, mirrordepth=0.2}  \begin{optexp} \beamsplitter[bsstyle=plate, compname=BS](A)(BS)(PD) \mirror[compname=M1](BS)(M1)(BS) \mirror[compname=M2, variable](BS)(M2)(BS) \lens[compname=L](BS)(PD) \optdetector[compname=Det, dettype=diode](BS)(PD) \addtopsstyle{Beam}{beamwidth=0.2, fillstyle=solid,fillcolor=green!20!white} \drawwidebeam(A){BS}{M1}{BS}{M2}{BS}{L}{Det} \end{optexp} \end{pspicture}  \end{document}   and the result is this    and I get "MiKTeX GPL Ghostscript 9.19: Unrecoverable error, exit code 1" error. When I remove optexp environment, so  \documentclass[pstricks,margin=12pt]{standalone}  \usepackage{pst-optexp}  \begin{document} \begin{pspicture}(3.2,5) \pnodes(0,3){A}(1,3){BS}(3,3){M1}(1,5){M2}(1,1){PD} \psset{mirrortype=extended, mirrordepth=0.2}   \beamsplitter[bsstyle=plate, compname=BS](A)(BS)(PD) \mirror[compname=M1](BS)(M1)(BS) \mirror[compname=M2, variable](BS)(M2)(BS) \lens[compname=L](BS)(PD) \optdetector[compname=Det, dettype=diode](BS)(PD) \addtopsstyle{Beam}{beamwidth=0.2, fillstyle=solid,fillcolor=green!20!white} \drawwidebeam(A){BS}{M1}{BS}{M2}{BS}{L}{Det}  \end{pspicture}  \end{document}   the result is     which is correct but optical components are behind beam. I use XeLatex. What am I doing wrong? Which packages are missing? Thank you (example is from manual "Drawing optical experimental setups" where the code works correctly). Effects of continuing after a total party wipe? I've had a couple of encounters so far where I stumbled into enemies that were higher level than expected and gotten wiped out. At the game over screen, I chose the option "Continue". After doing so, I didn't notice any negative consequences. I was plopped back just a few metres from the area I died, and was free to continue on as if nothing had happened. Am I missing something? Is there some negative effect from a party wipe? Covering map between orientable compact connected surfaces without boundary with genus $g$ Similar to a previous question I asked, this is the other question that I couldn't answer in an exam I gave for my Topology course:  Suppose $g_1,g_2$ are non-negative integers such that $2-2g_2$ divideds $2-2g_1$. I have to construct a covering map $S_{g_1} \rightarrow S_{g_2}$, where $S_g$ is denotes an orientable compact connected surface without boundary with genus $g$.  Now, I attempted to try this problem for surfaces with smaller genera, for example a 2-torus and a 2-sphere. Clearly $2-2g$ is the Euler Characteristic of the said surface, and by classification of surfaces we have to only consider connected sum of 2-tori. So, I have $\chi(S^2)=2$, and $\chi(T^2) = 0$, here we have $2$ dividing $0$, hence I have to construct a covering map from $T^2 \rightarrow S^2$, and I have no idea how to move forward.  Addendum: I have to got great answers to my question here but I had a doubt when it comes to the points being mapped, specifically in Giulio Bresciani's answer. Clearly the handles of the figure is mapped to the handles in the figure above, but I'm unable to understand the mapping of the twist of the cover (above figure) to the extreme handles of the base (the figure below). Any help? How to Identify Overfitting in Convolutional Neural network? I understand that dropout is used to reduce over fitting in the network. This is a generalization technique. In convolutional neural network how can I identify overfitting? One situation that I can think of is when I get training accuracy too high compared to testing or validation accuracy. In that case the model tries to overfit to the training samples and performs poorly to the testing samples. Is this the only way that indicates whether to apply dropout or should dropout be blindly added to the model hoping that it increases testing or validation accuracy Conditional expectation on more than one sigma-algebra I updated to Ubuntu 20.04. When I use the default terminal, everything is fine. But if try to use terminator, I cannot use sudo. I get permission denied. Again, only when using terminator.  How can I sudo from the terminator? I really would like to continue to use a terminator.  Edit: I just also noted that it cannot find make either. I guess it's all messed up. I'll try to uninstall it and install again I guess. Prove that $A+I$ is invertible if $A$ is nilpotent Possible Duplicate:          Given $A^{2012}=0$ prove that $A+I$ is invertible and find an expression for $(A+I)^{-1}$ in terms of $A$. ($I$ is the identity matrix).