Counting occournces of specific regular expression in a string in python
My regex is matching too much. How do I make it stop?
Although Ubuntu 16.04 release notes mention that:  The default VIM package has been built against python3 instead of python2.  Yet after I installed vim with the following command:  sudo apt-get install vim   And checked:  vim --version   It showed:  -python -python3   Is it a bug? How do I get vim with Python support? In  it says     To make gradient descent work correctly, we need to choose the learning rate η to be small enough that Equation (9) is a good approximation. If we don't, we might end up with $\Delta C&gt;0$, which obviously would not be good! At the same time, we don't want $\eta$ to be too small, since that will make the changes $\Delta v$ tiny, and thus the gradient descent algorithm will work very slowly. In practical implementations, $\eta$ is often varied so that Equation (9) remains a good approximation, but the algorithm isn't too slow. We'll see later how this works.   But just a few paragraphs before we established that $\Delta C\approx−\eta\nabla C⋅\nabla C=−\eta\|\nabla C\|^2$ is obviously always negative (for positive $\eta$). So how can $\Delta C$ be positive if we don't choose a small enough learning rate? What is meant there? Showing a compact metric space has a countable dense subset I know that this is separable, but that has not been covered by the text at this point. I believe my proof (below) to be correct, but not very rigorous. Assuming that it actually is correct, could someone please help me make it more formal? (If it's not correct, please help with the proof). Thanks.  Proof: Let $X$ be a compact metric space. Let $B_n = \{B(x,\frac1{n}) : x\in X\}$. be the collection of open balls centered at $x$. Let $\{x\}^{(n)}$ be the set of centers for some particular $n$. Then by compactness of $X$, there are also a finite number of centers for a particular $n$ (corresponding to each open ball).   [This is where I have trouble properly saying what's on my mind:]  Consider $B(x,r_0)$, where $r_0 = \frac{1}{n_0}$. When we decrease the magnitude of $r_0$ to $r_1$, we must still be able to cover $X$. Meaning some open ball(s) must be "formed" where $B(x,r_0)$ was once "covering". So by adding open balls, we also add to our collection of centers. This means at $B(x,r_0)$, there was originally a point $y \in B(x,r_0)$ s.t. $B(y,r') \subset B(x,r_0)$ for some $r'$. That is, $B(x,r_0)$ contained another point of $X$. Thus, by definition, $X$ contains a countable dense subset. Probability density and distribution function I am new to probability course and find concepts very confusing. I am learning maximum likelihood estimation and as a starting point for that do we find the density or the distribution?   In general, do we find the distribution from density or is it vice versa and how does one find it? For example, for Gaussian distribution do we find the density of a variable or the distribution so as to estimate unknown parameter A in the case x[n] = A + w[n] where w[n] are uncorrelated gaussian noise. This may sound too trivial but I am really confused. In many contexts I have come across where pdf = prob. density function and in some areas I find pdf = prob distribution function !! Whenever I do camera tracking in Blender the reconstruction is always zooming out or not on the axis. I have a great quality camera, but the end results of the camera tracking always has the model sliding. If you have a solution please tell me. What are point objects? How to stop Katoolin from crashing Ubuntu? I updated from 14.04 to 16.04 and used katoolin to add some Kali tools. After restart, the boot up of Linux ran codes, but stopped at a certain point never to load login. So I reinstalled 16.04, ran updates and tried again. This time, the boot menu was changed to Kali as well as the OS name (I'm using Windows 7 dual boot with Ubuntu); login started in Ubuntu style without user name, had to type in the name... then it goes to the logo screen never to log in.  How can I use katoolin without it affecting the boot menu interface? Does this happen when the user selects the option 'add Kali repositories and updates'? Are the Kali repositories necessary? I'd much rather just install the tools and not mess with the Ubuntu interface. Why do birds sitting on electric wires not get shocked? What causes 5 pink bars on 27" iMac (2011)? I've got a 27 inch iMac made in 2011 that displays 5 pink vertical bars on the screen. It won't boot properly. I ran the Apple Hardware Test and it came up clean.   Machine Specs:  Apple Subfamily:    Mid-2011  Apple Model No: A1312 (EMC 2429) Model ID:   iMac12,2 How to convert image file data in a byte array to a Bitmap? How do I move the "Show Applications" icon in Ubuntu Dock? Ubuntu 17.10 introduces the GNOME Shell with the  (based on  GNOME Shell extension) and it allows you to put the Dock on the bottom of the desktop:    However, there is no easy way to move the Show Applications icon (shown on the right) to the left of the Dock. There is no such setting in GNOME Control Center. There is already a  filed, but does anybody know any workaround until it gets fixed by Ubuntu Dock developers? How do I get a Seraph Crystal? Do we really need a [source-code] tag? The  tag doesn't appear to be very useful.  It's used in a variety of ways (for reading, writing, showing, transforming, compiling, translating, obfuscating, obtaining, ... source code) on 1747 questions right now, and doesn't appear to be adding any classification value to the site.  Can we get rid of it? How to find out the terminal command of an application? I want to use some applications shown on the Unity Launcher in a terminal, but I need to know the appropriate command to run them. How can I achieve that? Why can't I log into my minecraft account Convert from MySQL datetime to another format with PHP I have a datetime column in MySQL.   How can I convert it to the display as mm/dd/yy H:M (AM/PM) using PHP? Irfanview nearest equivalent for linux I have a TECNO Spark 2 running on Android 8.1 Oreo (Go Edition). Every time I try to install apps that require notification access, it says that the feature is not available.  How to fix it? Showing that a function is not differentiable Node Package Manager got corrupted in some way, now it cannot be installed I ran into a problem today when I decided to use npm update -g in a nodejs app directory. This was a bad decision, because it caused me to run into a .   The solution is to reinstall nodejs and npm. Unfortunately when I go to install npm using sudo apt-get install npm it doesn't work.  The full error in the terminal is here:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that  some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies:  npm : Depends: nodejs but it is not going to be installed    Depends: node-abbrev (&gt;= 1.0.4) but it is not going to be installed    Depends: node-ansi but it is not going to be installed    Depends: node-archy but it is not going to be installed    Depends: node-block-stream but it is not going to be installed    Depends: node-fstream (&gt;= 0.1.22) but it is not going to be installed    Depends: node-fstream-ignore but it is not going to be installed    Depends: node-github-url-from-git but it is not going to be installed    Depends: node-glob (&gt;= 3.1.21) but it is not going to be installed    Depends: node-graceful-fs (&gt;= 2.0.0) but it is not going to be installed    Depends: node-inherits but it is not going to be installed    Depends: node-ini (&gt;= 1.1.0) but it is not going to be installed    Depends: node-lockfile but it is not going to be installed    Depends: node-lru-cache (&gt;= 2.3.0) but it is not going to be installed    Depends: node-minimatch (&gt;= 0.2.11) but it is not going to be installed    Depends: node-mkdirp (&gt;= 0.3.3) but it is not going to be installed    Depends: node-gyp (&gt;= 0.10.9) but it is not going to be installed    Depends: node-nopt (&gt;= 2.1.1) but it is not going to be installed    Depends: node-npmlog but it is not going to be installed    Depends: node-once but it is not going to be installed    Depends: node-osenv but it is not going to be installed    Depends: node-read but it is not going to be installed    Depends: node-read-package-json (&gt;= 1.1.0) but it is not going to be installed    Depends: node-request (&gt;= 2.25.0) but it is not going to be installed    Depends: node-retry but it is not going to be installed    Depends: node-rimraf (&gt;= 2.2.2) but it is not going to be installed    Depends: node-semver (&gt;= 2.1.0) but it is not going to be installed    Depends: node-sha but it is not going to be installed    Depends: node-slide but it is not going to be installed    Depends: node-tar (&gt;= 0.1.18) but it is not going to be installed    Depends: node-which but it is not going to be installed E: Unable to correct problems, you have held broken packages.   What can I do to get npm properly installed and running again?  Thanks.