Tutorial by Examples: s

Display a map

<!DOCTYPE html> <html> <head> <meta charset='utf-8' /> <title></title> <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' /> <!-- find the latest library and style versions here: https://www.mapbox.com/m...

mapbox • Mapbox GL JS

Converting text case

In normal mode: ~ inverts the case of the character under the cursor, gu{motion} lowercases the text covered by {motion}, gU{motion} uppercases the text covered by {motion} Example (^ marks the cursor position): Lorem ipsum dolor sit amet. ^ Lorem ipSum dolor sit amet. ~ Lorem...

vim • Manipulating text

Deploying to Glassfish

So, you make first a .war file let's say a portlet of name <YOUR PLUGIN>.war. You wanna have it running on a glassfish domain under Liferay portal. Steps to success: Navigate to Control Panel -> Plugins Installation on Liferay Hit Install new portlets Hit Configuration Fill in to Dep...

liferay • Deploying a Plugin

Installation or Setup

Before to launch you to code with Pug, you need to have some prerequisits. You will need to install: NodeJS with NPM ExpressJS (optional) After installing NodeJS, you can check in your terminal the correct installation doing: $ node -v If successful, it will print the number of Node's ve...

jade • Getting started with jade

Rebasing before a code review

Summary This goal is to reorganize all of your scattered commits into more meaningful commits for easier code reviews. If there are too many layers of changes across too many files at once, it is harder to do a code review. If you can reorganize your chronologically created commits into topical com...

Git • Rebasing

Filter logs

git log --after '3 days ago' Specific dates work too: git log --after 2016-05-01 As with other commands and flags that accept a date parameter, the allowed date format is as supported by GNU date (highly flexible). An alias to --after is --since. Flags exist for the converse too: --before ...

Git • Browsing the history

Take a slice of a generator

Itertools "islice" allows you to slice a generator: results = fetch_paged_results() # returns a generator limit = 20 # Only want the first 20 results for data in itertools.islice(results, limit): print(data) Normally you cannot slice a generator: def gen(): n = 0 wh...

Python Language • Itertools Module

Raising Exceptions

If your code encounters a condition it doesn't know how to handle, such as an incorrect parameter, it should raise the appropriate exception. def even_the_odds(odds): if odds % 2 != 1: raise ValueError("Did not get an odd number") return odds + 1

Python Language • Exceptions

Catching Exceptions

Use try...except: to catch exceptions. You should specify as precise an exception as you can: try: x = 5 / 0 except ZeroDivisionError as e: # `e` is the exception object print("Got a divide by zero! The exception was:", e) # handle exceptional case x = 0 final...

Python Language • Exceptions

Re-raising exceptions

Sometimes you want to catch an exception just to inspect it, e.g. for logging purposes. After the inspection, you want the exception to continue propagating as it did before. In this case, simply use the raise statement with no parameters. try: 5 / 0 except ZeroDivisionError: print(&quo...

Python Language • Exceptions

Chain exceptions with raise from

In the process of handling an exception, you may want to raise another exception. For example, if you get an IOError while reading from a file, you may want to raise an application-specific error to present to the users of your library, instead. Python 3.x3.0 You can chain exceptions to show how t...

Python Language • Exceptions

Exceptions are Objects too

Exceptions are just regular Python objects that inherit from the built-in BaseException. A Python script can use the raise statement to interrupt execution, causing Python to print a stack trace of the call stack at that point and a representation of the exception instance. For example: >>&gt...

Python Language • Exceptions

IntelliJ IDEA + Cursive

Download and install the latest IDEA version. Download and install the latest version of the Cursive plugin. After restarting IDEA, Cursive should be working out of the box. Follow the user guide to fine-tune appearance, keybindings, code style etc. Note: Like IntelliJ, Cursive is a commercial pr...

clojure • Setting up your development environment

Installation of PyQt4

Suggested Install Method Windows: Download and run the binary setup file. Linux(Debian): Run this command in your command line: $ apt-get install python-qt4 pyqt4-dev-tools qt4-designer OS X : Run this command in your command line: $ brew install pyqt Install Manually You can also downloa...

pyqt • Getting started with pyqt

Partial stash

If you would like to stash only some diffs in your working set, you can use a partial stash. git stash -p And then interactively select which hunks to stash. As of version 2.13.0 you can also avoid the interactive mode and create a partial stash with a pathspec using the new push keyword. git ...

Git • Stashing

Sum of numbers from 1 to n

If I wanted to find out the sum of numbers from 1 to n where n is a natural number, I can do 1 + 2 + 3 + 4 + ... + (several hours later) + n. Alternatively, I could write a for loop: n = 0 for i in range (1, n+1): n += i Or I could use a technique known as recursion: def recursion(n): ...

Python Language • Recursion

Reading a file into a Buffer using streams

While reading content from a file is already asynchronous using the fs.readFile() method, sometimes we want to get the data in a Stream versus in a simple callback. This allows us to pipe this data to other locations or to process it as it comes in versus all at once at the end. const fs = require(...

Node.js • Filesystem I/O

Extracting N largest or N smallest items from an iterable

To find some number (more than one) of largest or smallest values of an iterable, you can use the nlargest and nsmallest of the heapq module: import heapq # get 5 largest items from the range heapq.nlargest(5, range(10)) # Output: [9, 8, 7, 6, 5] heapq.nsmallest(5, range(10)) # Output: [...

Python Language • Sorting, Minimum and Maximum

Getting JSON data

// get some data from stackoverflow fetch("https://api.stackexchange.com/2.2/questions/featured?order=desc&sort=activity&site=stackoverflow") .then(resp => resp.json()) .then(json => console.log(json)) .catch(err => console.log(err));

JavaScript • Fetch

Define polymorphic classes

The typical example is an abstract shape class, that can then be derived into squares, circles, and other concrete shapes. The parent class: Let's start with the polymorphic class: class Shape { public: virtual ~Shape() = default; virtual double get_surface() const = 0; virtual vo...

C++ • Polymorphism