Python Multiple Choice Questions & Answers (MCQs) on “Regular Expressions”.
1. Which module in Python supports regular expressions?
a) re
b) regex
c) pyregex
d) none of the mentioned
Answer: a
Clarification: re is a part of the standard library and can be imported using: import re.
2. Which of the following creates a pattern object?
a) re.create(str)
b) re.regex(str)
c) re.compile(str)
d) re.assemble(str)
Answer: c
Clarification: It converts a given string into a pattern object.
3. What does the function re.match do?
a) matches a pattern at the start of the string
b) matches a pattern at any position in the string
c) such a function does not exist
d) none of the mentioned
Answer: a
Clarification: It will look for the pattern at the beginning and return None if it isn’t found.
4. What does the function re.search do?
a) matches a pattern at the start of the string
b) matches a pattern at any position in the string
c) such a function does not exist
d) none of the mentioned
Answer: b
Clarification: It will look for the pattern at any position in the string.
5. What will be the output of the following Python code?
sentence = 'we are humans' matched = re.match(r'(.*) (.*?) (.*)', sentence) print(matched.groups())
a) (‘we’, ‘are’, ‘humans’)
b) (we, are, humans)
c) (‘we’, ‘humans’)
d) ‘we are humans’
Answer: a
Clarification: This function returns all the subgroups that have been matched.
6. What will be the output of the following Python code?
sentence = 'we are humans' matched = re.match(r'(.*) (.*?) (.*)', sentence) print(matched.group())
a) (‘we’, ‘are’, ‘humans’)
b) (we, are, humans)
c) (‘we’, ‘humans’)
d) ‘we are humans’
Answer: d
Clarification: This function returns the entire match.
7. What will be the output of the following Python code?
sentence = 'we are humans' matched = re.match(r'(.*) (.*?) (.*)', sentence) print(matched.group(2))
a) ‘are’
b) ‘we’
c) ‘humans’
d) ‘we are humans’
Answer: c
Clarification: This function returns the particular subgroup.
8. What will be the output of the following Python code?
sentence = 'horses are fast' regex = re.compile('(?Pw+) (?P ) matched = re.search(regex, sentence) print(matched.groupdict())w+) (?P w+)'
a) {‘animal’: ‘horses’, ‘verb’: ‘are’, ‘adjective’: ‘fast’}
b) (‘horses’, ‘are’, ‘fast’)
c) ‘horses are fast’
d) ‘are’
Answer: a
Clarification: This function returns a dictionary that contains all the matches.
9. What will be the output of the following Python code?
sentence = 'horses are fast' regex = re.compile('(?Pw+) (?P ) matched = re.search(regex, sentence) print(matched.groups())w+) (?P w+)'
a) {‘animal’: ‘horses’, ‘verb’: ‘are’, ‘adjective’: ‘fast’}
b) (‘horses’, ‘are’, ‘fast’)
c) ‘horses are fast’
d) ‘are’
Answer: b
Clarification: This function returns all the subgroups that have been matched.
10. What will be the output of the following Python code?
sentence = 'horses are fast' regex = re.compile('(?Pw+) (?P ) matched = re.search(regex, sentence) print(matched.group(2))w+) (?P w+)'
a) {‘animal’: ‘horses’, ‘verb’: ‘are’, ‘adjective’: ‘fast’}
b) (‘horses’, ‘are’, ‘fast’)
c) ‘horses are fast’
d) ‘are’
Answer: d
Clarification: This function returns the particular subgroup.