Data Intro for Librarians: Reference

Key Points

Introduction to Library Carpentry	Don’t be scared to ask for help
Jargon Busting	It helps to share what you know and don’t know about software development and data science jargon
Foundations	Data structures should be consistent and predictable Consider using semantic elements or data identifiers to data directories Fit and adapt your data structure to your work Apply naming conventions to directories and file names to identify them, to create associations between data elements, and to assist with the long term readability and comprehension of your data structures
Introduction to Regular Expressions	Regular expressions are powerful tools for pattern matching Check your regex with: regex101 https://regex101.com/, rexegper http://regexper.com/, or myregexp http://myregexp.com/. Test yourself with: Regex Crossword https://regexcrossword.com/ or our The Multiple Choice Quiz http://data-lessons.github.io/library-data-intro/05-quiz/.
Regular Expressions basics	Match caracters by using characters as a regex {“Add modifiers to change default behavior”=>”case sensitive.”} Operators
Quantifiers in Regular Expressions	Use \ to escape a special character Use * to match zero or more characters Use + to match one or more characters Use ? for making an operator optional Use {} to specify how many times something will occur, or a range
Regular expressions exercises	Select upper case or lower case; match any character; assert the position at the start and end of line; add a word boundary
Introduction to Data - Multiple Choice Quiz	Regular expressions reference guide
Introduction to Data - Multiple Choice Quiz (answers)"	Regular expressions answer sheet

Data Intro Cheat Sheet

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Regular Expression

• [] defines a range of characters.
• . matches any character.
• \ is used to escape the following character when that character is a special character. So, for example, a regular expression that found ‘.com’ would be \\.com because . is a special character that matches any character.
• \d matches any single digit.
• \w matches any part of word character (equivalent to [A-Za-z0-9]).
• \s matches any space, tab, or newline.
• ^ asserts the position at the start of the line. So what you put after it will only match if they are the first characters of a line.
• $ asserts the position at the end of the line. So what you put before it will only match if they are the last characters of a line.
• \b adds a word boundary. Putting this either side of a stops the regular expression matching longer variants of words.
• * matches the preceding element zero or more times. For example, ab*c matches ‘ac’, ‘abc’, ‘abbbc’, etc.
• + matches the preceding element one or more times. For example, ab+c matches ‘abc’, ‘abbbc’ but not ‘ac’.
• ? matches when the preceding character appears zero or one time.
• {VALUE} matches the preceding character the number of times define by VALUE; ranges can be specified with the syntax {VALUE,VALUE}.
• | means or.