Q1. What is a regular expression? A1. A regular expression is a sequence of characters that defines a search pattern, used to match and manipulate strings.
Q2. How do you import the regular expressions module in Python? A2. You import the regular expressions module by using the statement: import re.
Q3. What function is used to search for a pattern in a string using regular expressions? A3. The re.search() function is used to search for a pattern in a string.
Q4. How do you check if a pattern matches a string using regular expressions? A4. You can use the re.match() function to check if a pattern matches a string at the beginning of the string.
Q5. What function is used to find all occurrences of a pattern in a string using regular expressions? A5. The re.findall() function is used to find all occurrences of a pattern in a string.
Q6. How do you substitute a pattern in a string using regular expressions? A6. You can use the re.sub() function to substitute a pattern in a string with a specified replacement.
Q7. What metacharacter is used to match any character except a newline? A7. The dot (.) metacharacter is used to match any character except a newline.
Q8. How do you specify a range of characters in a regular expression? A8. You can specify a range of characters using square brackets ([]). For example, [a-z] matches any lowercase letter.
Q9. What metacharacter is used to match zero or more occurrences of the preceding character or group? A9. The asterisk (*) metacharacter is used to match zero or more occurrences of the preceding character or group.
Q10. How do you match one or more occurrences of the preceding character or group in a regular expression? A10. You can use the plus (+) metacharacter to match one or more occurrences of the preceding character or group.
Q11. What metacharacter is used to match the beginning of a string in a regular expression? A11. The caret (^) metacharacter is used to match the beginning of a string.
Q12. How do you match the end of a string in a regular expression? A12. You can use the dollar ($) metacharacter to match the end of a string.
Q13. What metacharacter is used to match a word boundary in a regular expression? A13. The backslash (\b) metacharacter is used to match a word boundary.
Q14. How do you specify the number of occurrences of a character or group in a regular expression? A14. You can use curly braces ({}) to specify the number of occurrences. For example, {3} matches exactly three occurrences.
Q15. What metacharacter is used to match any digit character in a regular expression? A15. The backslash (\d) metacharacter is used to match any digit character.
Q16. How do you match any non-digit character in a regular expression? A16. You can use the backslash (\D) metacharacter to match any non-digit character.
Q17. What metacharacter is used to match any whitespace character in a regular expression? A17. The backslash (\s) metacharacter is used to match any whitespace character.