Download - The Bastards Book of Regular Expressions

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Sorting a police blotter 155Start loose and simpleLet’s try this the sloppiest way we can: use the dot operator with the lazy-star operator, *? tocapture everything that is not one of the actual labels:Find (.*?)Record ID(.*?)Incident Date(.*?)Time(.*?)Division(.*?)Title(.*?)Location(.*?)Summary(.*?Contact\s*& NumberNote: There’s apparently always a line break between “PD Contact” and “& Number”Why do we use the star instead of the plus? Some of those fields, such as “Adults Arrested”, maybe empty.However, this pattern is not quite there. Some of the records have multiple line breaks within certainfields, such as the “Summary”. The dot operator does not match newline characters. So we simplyneed to change all the instances of (.*?) to: ((?:.|\n)*?). That looks more complicated that itsounds, because I threw in a non-capturing group. But basically, we’ve changed the pattern to matcheither a dot (i.e all newline characters) or a newline character (i.e. everything).Find ((?:.|\n)*?)Record ID((?:.|\n)*?)Incident Date((?:.|\n)*?)Time((?:.|\n)*?)Division((?:.|\n)*?Contact *\n& NumberReplace \1\n\2\n\3\n\4\n\5\n\6\n\7\n\8\n\9Using the above regex on our sample text, we end up with nine separate lines, each one correspondingto a data field (we don’t really need the labels at this point):17836March 5, 20136:59:00 AMSand Creek -- Shift IOther190X Carmel DriveSand Creek Officers were sent to the Westwind Apartments. The reporting par\ty said her boyfriend was cut with a sword by a neighbor. Medical personnel\staged and officers responded to the scene. Investigation revealed that Se\an Doe went to Guy Incognito's apartment with a Samurai sword. Doe swung th\e sword at Incognito's face when Incognito opened his door. Incognito caugh\t the blade in both hands and he was able wrestle the sword away. Incognito\and Doe were bleeding extensively. Officers arrested Doe at his apartment.\Incognito and Doe were transported to Memorial Central for treatment. Both\are in stable condition and awaiting surgery.Sean DoeLt. Strassburg-Aldal - 444-7270
Sorting a police blotter 156I used newlines in the replacement pattern just to produce something easier to read. You could’veused tab characters which would allow you to paste the result directly into Excel:A single tab-delimited police report pasted into ExcelAdding a report-ending delimiterIf you try to apply the regex above to the entire page of 10 reports, you’ll find that they don’t copyand-pasteso easy into Excel. This is because some of the reports contain extra line breaks. Andcopying/pasting line breaks into Excel will create problems:The entire tab-delimited reports list with gratuitous line breaks included, pasted into ExcelThere’s a few hacks we can use to clean this up. I think the easiest approach is to adjust the Replacepattern:Replace \1\t\2\t\3\t\4\t\5\t\6\t\7\t\8\t\9--END--You can use whatever arbitrary string you want there. The important thing is to have that stringdenote the end of each report. An example result is:17838 March 5, 2013 2:41:00 PM Falcon – Shift II Burglary 3400 block of Sinton RdOn 03-05-13, Officers from the Colorado Springs Police Department were dispatchedto Sinton Rd regarding a burglary. Upon arrival they learned approximately 6 camperstyle vehicles/trailers had been broken into from 03-04-13 6pm to 03-05-13 12:00 pm. Ifyou were a victim of one of these burglaries please contact the Colorado Springs PoliceDepartment at 444-7000. Lt. Buckley - 444-7240–END–
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The Bastards Book ofRegular Express
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CONTENTSOptionality and alternation
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CONTENTSSwitching visualizations (T
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Regular Expressions are for Everyon
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Regular Expressions are for Everyon
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Getting Started6
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Finding a proper text editor 8Notep
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Finding a proper text editor 10Edit
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Finding a proper text editor 12Text
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Finding a proper text editor 14does
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Finding a proper text editor 16Yest
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Finding a proper text editor 18A do
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A better Find-and-Replace 20The lim
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A better Find-and-Replace 22Using R
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Your first regex 24helloThe Find-an
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Your first regex 26The regex syntax
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Your first regex 28Double-bounded
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Your first regex 30AnswerFind \bcat
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Removing emptinessIt’s funny how
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Removing emptiness 34Now let’s do
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Removing emptiness 36…as opposed
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Removing emptiness 38Replacement in
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Match one-or-more with the plus sig
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Match zero-or-more with the star si
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Specific and limited repetition 501
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Specific and limited repetition 52E
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Specific and limited repetition 54C
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Anchors: A way to trim emptinessIn
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Anchors: A way to trim emptiness 58
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Matching any letter, any number 64A
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Matching any letter, any number 66W
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Matching any letter, any number 68[
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Matching any letter, any number 70R
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Matching any letter, any number 72F
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Matching any letter, any number 74A
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Negative character sets 76$1,200.00
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Negative character sets 78\W+Exerci
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Capture, Reuse 80Find (ba)+Matches
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Capture, Reuse 82.- then the 1st ba
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Capture, Reuse 84In English We are
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Capture, Reuse 86ApplesOraclesOrang
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Capture, Reuse 8805-14-8912-03-9803
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Capture, Reuse 90Mary asked: "What
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Optionality and alternationThe two
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Optionality and alternation 94Answe
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Optionality and alternation 96Studi
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Optionality and alternation 98You m
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Laziness and greediness 100Being to
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Laziness and greediness 102Replace
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Page 113 and 114: Lookarounds 106cat(?=s)- will match
Page 115 and 116: Lookarounds 108`(?
Page 117 and 118: Lookarounds 110ExerciseGiven the fo
Page 119 and 120: Lookarounds 112City,CountryAlbuquer
Page 121 and 122: Lookarounds 114Given this list of c
Page 123 and 124: Lookarounds 116100,J.D. Salinger Av
Page 125 and 126: Lookarounds 1186,300|Apples|New Yor
Page 127 and 128: Lookarounds 120^(\d+) Record ID (\w
Page 129 and 130: Lookarounds 122d. Remove all asides
Page 131 and 132: From Data to HTML (TODO)This chapte
Page 133 and 134: From Data to HTML (TODO) 126Turning
Page 135 and 136: The ExercisesI’ve never been one
Page 137 and 138: Data Cleaning with the Stars 130LOR
Page 139 and 140: Data Cleaning with the Stars 132[GM
Page 141 and 142: Finding needles in haystacks (TODO)
Page 143 and 144: Changing phone format (TODO)Todo: T
Page 145 and 146: Changing phone format (TODO) 138Exe
Page 147 and 148: Changing phone format (TODO) 140Ans
Page 149 and 150: Changing phone format (TODO) 142`1-
Page 151 and 152: Changing phone format (TODO) 144(\d
Page 153 and 154: Dating, Associated Press Style (TOD
Page 161: Sorting a police blotter 154Sloppy
Page 165 and 166: Converting XML to tab-delimited dat
Page 167 and 168: Converting XML to tab-delimited dat
Page 169 and 170: Cleaning up Microsoft Word HTML(TOD
Page 171 and 172: Cleaning up OCR Text (TODO)Image sc
Page 173 and 174: Moving forwardThank you for taking
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