Introduction to Data - Multiple Choice Quiz (answers)"
Last updated on 2023-04-24 | Edit this page
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Overview
Questions
- What does
Fr[ea]nc[eh]match?
Objectives
- Test knowledge of use of regular expressions in searches
Library Carpentry Week One: Introduction to Data
Exercise Answers
What does Fr[ea]nc[eh] match?
- this matches
France,French,Frence, andFranch. It would find words where there were characters either side of these soFrancer,foobarFrench, orFranch911.
What does Fr[ea]nc[eh]$ match?
- this matches
France,French,Frence, andFranchat the end of a line. It would find words where there were characters before these sofoobarFrench.
What would match the strings French and
France only that appear at the beginning of a line?
-
^France|^FrenchThis would also find words where there were characters afterFrenchsuch asFrenchness.
How do you match the whole words colour and
color (case insensitive)?
- In real life, you should only come across the case
insensitive variations
colour,color,Colour,Color,COLOUR, andCOLOR(rather than, say,coLour. So one option would be\b[Cc]olou?r\b|\bCOLOU?R\b. This can, however, get quickly quite complex. An option we’ve not discussed is to take advantage of the/delimiters and add an ignore case flag: so/colou?r/iwill match all case insensitive variants ofcolourandcolor.
How would you find the whole-word headrest and or the
2-gram head rest but not head rest (that is,
with two spaces between head and rest?
-
\bhead ?rest\b. Note that although\bhead\s?rest\bdoes work, it would also match zero or one tabs or newline characters betweenheadandrest. In most real world cases it should, however, be fine :)
How would you find a 4 letter word that ends a string and is preceded by at least one zero?
0+[a-z]{4}\b
How do you match any 4 digit string anywhere?
-
\d{4}. Note this will match 4 digit strings only but will find them within longer strings of numbers.
How would you match the date format dd-MM-yyyy?
-
\b\d{2}-\d{2}-\d{4}\bIn most real world situations, you are likely to want word bounding here (but it may depend on your data).
How would you match the date format dd-MM-yyyy or
dd-MM-yy at the end of a string only?
\d{2}-\d{2}-\d{2,4}$
How would you match publication formats such as
British Library : London, 2015 and
Manchester University Press: Manchester, 1999?
-
.* : .*, \d{4}You will find that this matches any text you put beforeBritishorManchester. In this case, this regular expression does a good job on the first look up and may be need to be refined on a second depending on your real world application.
Multiple Choice Quiz Answers
- Q1. C
- Q2. A
- Q3. B
- Q4. B
- Q5. C
- Q6. B
- Q7. C
- Q8. A
- Q9. C
- Q10. A
- Q11. B
- Q12. A
Key Points
- Regular expressions answer sheet