pwpearson

Regex
"(\$)([0-9]*),?([0-9]*),?([0-9]*)(\.?)([0-9]*+ *)"

Replace
"$1$2$3$4$5$6"


Finds "$999,999,999.99 " literal and replaces it with "$999999999.99 "

pwpearson

FILE SPACING:

 # double space a file
 sed G

 # double space a file which already has blank lines in it. Output file
 # should contain no more than one blank line between lines of text.
 sed '/^$/d;G'

pwpearson

PSQL

Magic words:

psql -U postgres

If run with -E flag, it will describe the underlaying queries of the \ commands (cool for learning!).

Most \d commands support additional param of __schema__.name__ and accept wildcards like *.*

pwpearson

Typography

Headings

Headings from h1 through h6 are constructed with a # for each level:

# h1 Heading
## h2 Heading
### h3 Heading

pwpearson

val factorialOfFive = {1 to 5}.toList.reduceLeft(_*_)

pwpearson

10 Scala One Liners to Impress Your Friends

Here are 10 one-liners which show the power of scala programming, impress your friends and woo women; ok, maybe not. However, these one liners are a good set of examples using functional programming and scala syntax you may not be familiar with. I feel there is no better way to learn than to see real examples.

Updated: June 17, 2011 - I'm amazed at the popularity of this post, glad everyone enjoyed it and to see it duplicated across so many languages. I've included some of the suggestions to shorten up some of my scala examples. Some I intentionally left longer as a way for explaining / understanding what the functions were doing, not necessarily to produce the shortest possible code; so I'll include both.

1. Multiple Each Item in a List by 2

The map function takes each element in the list and applies it to the corresponding function. In this example, we take each element and multiply it by 2. This will return a list of equivalent size, compare to o

pwpearson

-- Find more at http://iterm.sourceforge.net/scripting.shtml

launch "iTerm"

tell application "iTerm"
 activate

 -- ssh in split panes to my varnish stack
 set myterm to (make new terminal)
 tell myterm

pwpearson

#!/bin/bash
read -r -d '' script <<'EOF'
on run argv
tell application "iTerm"
    activate
    set myterm to (make new terminal)
    tell myterm
        launch session "Default"
        tell the last session
            repeat with arg in argv

pwpearson

Keyboard shortcuts

The Spark Notebook has two different keyboard input modes. Edit mode allows you to type code/text into a cell and is indicated by a green cell border. Command mode binds the keyboard to notebook level actions and is indicated by a grey cell border.

####MacOS modifier keys

⌘: Command	⌃: Control
⌥: Option	⇧: Shift
↩: Return	␣: Space

pwpearson

// This example shows how to use row_number and rank to create
// a dataframe of precipitation values associated with a zip and date
// from the closest NOAA station
 
import org.apache.spark.sql.expressions.Window
import org.apache.spark.sql.functions._

// mocked NOAA weather station data
case class noaaData(zip:String,station:String,date:Long,value:String=null,distance:Int)
val t = Seq(