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Capture, Reuse 83Roosevelt, Franklin D.Walker, Mary E.Berners-Lee, Tim J.Williams, Serena J.The main variation here is that we need a third capturing group to contain the middle initial. Also,the names may contain hyphens.Find ([\w-]+), ([\w-]+) ([A-Z].)Replace $2 $3 $1A couple of notes:1. The hyphen inside square brackets has to be escaped, because, the hyphen in that context is aspecial character that acts as a range (e.g. from A to Z, as we see in the third-capturing group).2. The dot character – . – has to be escaped, because it is a special regex character. In fact, it isa very powerful character that we’ll learn about in a [later chapter]{#dot-character}.Correcting dates with capturing groupsIn a previous chapter, we encountered the problem of trying to fix the year-value on a list of dates:12/24/2012, $50.0012/25/2012, $50.0012/28/2012, $102.001/1/2012, $2012.001/2/2012, $32.001/6/2012, $52012.001/12/2012, $642.001/13/2012, $500.001/20/2013, $100.002/1/2013, $2012.20If this list is chronological, then the data-entry person forgot to go from 2012 to 2013 when Januaryrolled around.Let’s start with how we selectively target the January dates:Find 1/\d+/2012
Capture, Reuse 84In English We are looking for a 1, followed by a forward-slash, followed by one-or-more numericaldigits, and then another forward-slash and the sequence 2012.Using a capturing group, we wrap the non-year part of the date in parentheses. And then we usethe backreference $1 to retrieve the value to use in the replacement:Find (1/\d+)/2012Replace $1/2013In Sublime Text 2, this is what the operation looks like:Sublime Text 2Remember that some variations of regex, including the one used in TextWrangler, the backreferenceinvolves a backslash instead of a dollar sign:
Page 1:
The Bastards Book ofRegular Express
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CONTENTSOptionality and alternation
Page 7 and 8:
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
Page 39 and 40: Removing emptinessIt’s funny how
Page 41 and 42: Removing emptiness 34Now let’s do
Page 43 and 44: Removing emptiness 36…as opposed
Page 45 and 46: Removing emptiness 38Replacement in
Page 47 and 48: Match one-or-more with the plus sig
Page 55 and 56: Match zero-or-more with the star si
Page 57 and 58: Specific and limited repetition 501
Page 59 and 60: Specific and limited repetition 52E
Page 61 and 62: Specific and limited repetition 54C
Page 63 and 64: Anchors: A way to trim emptinessIn
Page 65 and 66: Anchors: A way to trim emptiness 58
Page 71 and 72: Matching any letter, any number 64A
Page 73 and 74: Matching any letter, any number 66W
Page 75 and 76: Matching any letter, any number 68[
Page 77 and 78: Matching any letter, any number 70R
Page 79 and 80: Matching any letter, any number 72F
Page 81 and 82: Matching any letter, any number 74A
Page 83 and 84: Negative character sets 76$1,200.00
Page 85 and 86: Negative character sets 78\W+Exerci
Page 87 and 88: Capture, Reuse 80Find (ba)+Matches
Page 89: Capture, Reuse 82.- then the 1st ba
Page 93 and 94: Capture, Reuse 86ApplesOraclesOrang
Page 95 and 96: Capture, Reuse 8805-14-8912-03-9803
Page 97 and 98: Capture, Reuse 90Mary asked: "What
Page 99 and 100: Optionality and alternationThe two
Page 101 and 102: Optionality and alternation 94Answe
Page 103 and 104: Optionality and alternation 96Studi
Page 105 and 106: Optionality and alternation 98You m
Page 107 and 108: Laziness and greediness 100Being to
Page 109 and 110: Laziness and greediness 102Replace
Page 111 and 112: Laziness and greediness 104With the
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
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Finding needles in haystacks (TODO)
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Changing phone format (TODO)Todo: T
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Changing phone format (TODO) 138Exe
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Changing phone format (TODO) 140Ans
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Changing phone format (TODO) 142`1-
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Changing phone format (TODO) 144(\d
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Dating, Associated Press Style (TOD
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Sorting a police blotter 154Sloppy
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Sorting a police blotter 156I used
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Converting XML to tab-delimited dat
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Converting XML to tab-delimited dat
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Cleaning up Microsoft Word HTML(TOD
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Cleaning up OCR Text (TODO)Image sc
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Moving forwardThank you for taking
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