10_RegularExpressions - CS 200 Regular Expressions A Ubiquitous Tool for Manipulating Text CS 200 Spring 2016 1 Regular Expressions The Executive

10_RegularExpressions - CS 200 Regular Expressions A...

This preview shows page 1 - 7 out of 22 pages.

CS 200 CS 200 Spring 2016 Regular Expressions 1 Regular Expressions A Ubiquitous Tool for Manipulating Text
Image of page 1
CS 200Fall 2016 Regular Expressions Regular expressions are a way of representing patterns in text Why are they useful? finding text that matches a pattern replacing it with something else — saving you time Where do you find them? major word processors (e.g. MS Word) obscure keyword: “wildcards” most text editors (eg BBEdit, TextWrangler, TextPad, vi, emacs) obscure keyword: “grep” various command line tools UNIX grep, find Windows XP's findstr etc, etc, etc... 2 The Executive Summary
Image of page 2
CS 200Fall 2016 Regular Expressions To import this data into a FileMaker table, we need separate fields for given & family names a separate field for the * ’s flagging privacy So we want to replace • • • : * Ferraro , David Joseph : • • • • • • : Shillington , Tara Dawn : • • • by • • • : * : David Joseph : Ferraro : • • • • • • :: Tara Dawn : Shillington : • • • 3 00035091:ygavet: Gavet , Yann ::math:NN:ND 92013945:alaustaris: * Ustaris , Arsenyk Lord Alexis :math:math:4A:H 95011647:awowkodaw: Wowkodaw , Andrij :sy de:eng:4B:H 95014052:lpdcunha: D'Cunha , Larry Paul :sy de:eng:4B:H 95032773:djferraro: * Ferraro , David Joseph :sy de:eng:4B:H 95044104:majarvis: Jarvis , Michael Andrew :civ e:eng:4B:H 95075344:hzshahid: Shahid , Hasan Ziaulhaq ::sci:4N:H 95082835:sfodell: O'Dell , Shane Fund ::sci:4N:H 95084257:jmkonik: Konik , Jason :sy de:eng:4B:H 96001912:kmemberson: * Emberson , Kathleen Marie :math:math:4A:H 96007474:ajbehm: * Behm , Aaron Jeffrey :math:math:4B:H 96007733:tdshillington: Shillington , Tara Dawn :phys:sci:4B:H 96012020:mdoris: Doris , Matthew :phys:sci:4B:H • • • (1) These student ID numbers were randomly generated. Example Problem 1 — Reformat a Classlist (1)
Image of page 3
CS 200Fall 2016 Regular Expressions These files having been generated by Audio Hijack Pro as it records music from a digital cable channel (to play in my car via an iPod) That is, for convenience we want to change a sequence of date-time stamped file names generated by an audio recording program RC 741 20061112 1500.m4a to a more usable sequence having the form 4 RC 741 20061112 1500.m4a RC 741 20061112 1501.m4a RC 741 20061112 1502.1.m4a RC 741 20061112 1502.m4a RC 741 20061112 1503.m4a RC 741 20061112 1504.1.m4a RC 741 20061112 1504.m4a RC 741 20061112 1505.m4a RC 741 20061112 1506.m4a RC 741 20061112 1507.1.m4a RC 741 20061112 1507.m4a RC 741 20061112 1508.m4a RC 741 20061112 1509.1.m4a RC 741 20061112 1509.m4a RC 741 20061112 1510.m4a RC 741 20061112 1511.1.m4a • • • Change Baroque 01.m4a Baroque 02.m4a Baroque 03.m4a Baroque 04.m4a Baroque 05.m4a Baroque 06.m4a Baroque 07.m4a Baroque 08.m4a Baroque 09.m4a Baroque 10.m4a Baroque 11.m4a Baroque 12.m4a Baroque 13.m4a Baroque 14.m4a Baroque 15.m4a Baroque 16.m4a • • • To Example Problem 2 — Changing a Large Number of File
Image of page 4
CS 200Fall 2016 Regular Expressions We want to change dates represented in the European “Day Month Year” style 25 Sep 1986 to a format more suitable for importation into an SQL database 09–25–1986 5 'ALG','1','15.00','Written problem',' 25 Sep 1986 ' 'ALG','2','15.00','Written problem',' 19 Oct 1986 ' 'ALG','3','20.00','Midterm',' 29 Oct 1986 ' 'ALG','4','10.00','Group problem',' 15 Nov 1986 ' 'ALG','5','10.00','Oral presentation',' 27 Nov 1986 ' 'ALG','6','30.00','Final Exam',' 14 Dec 1986 ' 'BIOL','1','10.00','Written assignment',' 24 Sep 1986 ' 'BIOL','2','15.00','Written assignment',' 20 Oct 1986 ' 'BIOL','3','30.00','Midterm',' 16 Nov 1986 ' • • • Example Problem 3 — Change Date Format
Image of page 5
CS 200Fall 2016 Regular Expressions Source text: He is a rat.
Image of page 6
Image of page 7

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture