Python Regular Expression - Exercises, Practice, Solution
This resource offers a total of 290 Python Regular Expression problems for practice. It includes 58 main exercises, each accompanied by solutions, detailed explanations, and four related problems.
A regular expression (or RE) specifies a set of strings that matches it; the functions in this module let you check if a particular string matches a given regular expression.
You may read our Python regular expression tutorial before solving the following exercises.
[An Editor is available at the bottom of the page to write and execute the scripts.]
1. Allowed Characters Check
Write a Python program to check that a string contains only a certain set of characters (in this case a-z, A-Z and 0-9).
2. a Followed by 0+ b's
Write a Python program that matches a string that has an a followed by zero or more b's.
3. a Followed by 1+ b's
Write a Python program that matches a string that has an a followed by one or more b's.
4. a Followed by 0 or 1 b
Write a Python program that matches a string that has an a followed by zero or one 'b'.
5. a Followed by Exactly 3 b's
Write a Python program that matches a string that has an a followed by three 'b'.
6. a Followed by 2 to 3 b's
Write a Python program that matches a string that has an a followed by two to three 'b'.
7. Lowercase with Underscore
Write a Python program to find sequences of lowercase letters joined by an underscore.
8. Uppercase Followed by Lowercase
Write a Python program to find the sequences of one upper case letter followed by lower case letters.
9. a ... ending in b
Write a Python program that matches a string that has an 'a' followed by anything ending in 'b'.
10. Word at Start
Write a Python program that matches a word at the beginning of a string.
11. Word at End
Write a Python program that matches a word at the end of a string, with optional punctuation.
12. Word Containing z
Write a Python program that matches a word containing 'z'.
13. z in Middle
Write a Python program that matches a word containing 'z', not the start or end of the word.
14. Alphanumeric Underscore Only
Write a Python program to match a string that contains only upper and lowercase letters, numbers, and underscores.
15. Starts with Specific Number
Write a Python program that starts each string with a specific number.
16. Remove Leading Zeros from IP
Write a Python program to remove leading zeros from an IP address.
17. Number at End
Write a Python program to check for a number at the end of a string.
18. Search 1-3 Digit Numbers
Write a Python program to search for numbers (0-9) of length between 1 and 3 in a given string.
"Exercises number 1, 12, 13, and 345 are important"
19. Search Literal Strings
Write a Python program to search for literal strings within a string.
Sample text : 'The quick brown fox jumps over the lazy dog.'
Searched words : 'fox', 'dog', 'horse'
20. Literal String with Position
Write a Python program to search for a literal string in a string and also find the location within the original string where the pattern occurs.
Sample text : 'The quick brown fox jumps over the lazy dog.'
Searched words : 'fox'
21. Find Substrings
Write a Python program to find the substrings within a string.
Sample text :
'Python exercises, PHP exercises, C# exercises'
Pattern :
'exercises'
Note: There are two instances of exercises in the input string.
22. Substring Occurrence and Position
Write a Python program to find the occurrence and position of substrings within a string.
23. Swap Spaces and Underscores
Write a Python program to replace whitespaces with an underscore and vice versa.
24. Extract Date from URL
Write a Python program to extract year, month and date from an URL.
25. Convert Date Format
Write a Python program to convert a date of yyyy-mm-dd format to dd-mm-yyyy format.
26. Words Starting with P
Write a Python program to match if two words from a list of words start with the letter 'P'.
27. Extract Numbers
Write a Python program to separate and print the numbers in a given string.
28. Words Starting with a/e
Write a Python program to find all words starting with 'a' or 'e' in a given string.
29. Numbers and Positions
Write a Python program to separate and print the numbers and their position in a given string.
30. Abbreviate Road
Write a Python program to abbreviate 'Road' as 'Rd.' in a given string.
31. Replace Delimiters with Colon
Write a Python program to replace all occurrences of a space, comma, or dot with a colon.
32. Replace Max 2 Delimiters
Write a Python program to replace maximum 2 occurrences of space, comma, or dot with a colon.
33. Find 5-letter Words
Write a Python program to find all five-character words in a string.
34. Find 3-5 Letter Words
Write a Python program to find all three, four, and five character words in a string.
35. Words 4+ Letters
Write a Python program to find all words that are at least 4 characters long in a string.
36. Camel to Snake
Write a Python program to convert a camel-case string to a snake-case string.
37. Snake to Camel
Write a python program to convert snake-case string to camel-case string.
38. Extract Quoted Values
Write a Python program to extract values between quotation marks of a string.
39. Remove Extra Spaces
Write a Python program to remove multiple spaces from a string.
40. Remove All Whitespace
Write a Python program to remove all whitespaces from a string.
41. Remove Non-Alphanumerics
Write a Python program to remove everything except alphanumeric characters from a string.
42. Find URLs
Write a Python program to find URLs in a string.
43. Split into Uppercase Letters
Write a Python program to split a string into uppercase letters.
44. Case-insensitive Replace
Write a Python program to do case-insensitive string replacement.
45. Remove ANSI Sequences
Write a Python program to remove ANSI escape sequences from a string.
46. Find Adverbs with Position
Write a Python program to find all adverbs and their positions in a given sentence.
Sample text : "Clearly, he has no excuse for such behavior."
47. Split with Multiple Delimiters
Write a Python program to split a string with multiple delimiters.
Note : A delimiter is a sequence of one or more characters used to specify the boundary between separate, independent regions in plain text or other data streams. An example of a delimiter is the comma character, which acts as a field delimiter in a sequence of comma-separated values.
48. Check Decimal Precision
Write a Python program to check a decimal with a precision of 2.
49. Remove Short Words
Write a Python program to remove words from a string of length between 1 and a given number.
50. Remove Parenthesis Area
Write a Python program to remove the parenthesis area in a string.
Sample data : ["example (.com)", "w3resource", "github (.com)", "stackoverflow (.com)"]
Expected Output:
example
w3resource
github
stackoverflow
Click me to see the solution
51. Insert Spaces Before Capitals
Write a Python program to insert spaces between words starting with capital letters.
52. Evaluate Expression
Write a Python program that reads a given expression and evaluates it.
Terms and conditions:
The expression consists of numerical values, operators and parentheses, and the ends with '='.
The operators includes +, -, *, / where, represents, addition, subtraction, multiplication and division.
When two operators have the same precedence, they are applied to left to right.
You may assume that there is no division by zero.
All calculation is performed as integers, and after the decimal point should be truncated
Length of the expression will not exceed 100.
-1 ? 10 9 = intermediate results of computation = 10 9
Click me to see the solution
53. Remove Lowercase Substrings
Write a Python program to remove lowercase substrings from a given string.
54. Concatenate Consecutive Numbers
Write a Python program to concatenate the consecutive numbers in a given string.
Original string:
Enter at 1 20 Kearny Street. The security desk can direct you to floor 1 6. Please have your identification ready.
After concatenating the consecutive numbers in the said string:
Enter at 120 Kearny Street. The security desk can direct you to floor 16. Please have your identification ready.
Click me to see the solution
55. Convert to Snake Case
Write a Python program to convert a given string to snake case.
Sample Output:
java-script
gd-script
btw...-what-*-do*-you-call-that-naming-style?-snake-case?
Click me to see the solution
56. Longest Iterable
Write a Python program that takes any number of iterable objects or objects with a length property and returns the longest one.
Sample Output:
Orange
[1, 2, 3, 4, 5]
Java
Python
Click me to see the solution
57. Word Starts & Ends with Vowel
Write a Python program that checks whether a word starts and ends with a vowel in a given string. Return true if a word matches the condition; otherwise, return false.
Sample Data:
("Red Orange White") -> True
("Red White Black") -> False
("abcd dkise eosksu") -> True
Click me to see the solution
58. Consecutive Vowel Check
Write a Python program that takes a string with some words. For two consecutive words in the said string, check whether the first word ends with a vowel and the next word begins with a vowel. If the program meets the condition, return true, otherwise false. Only one space is allowed between the words.
Sample Data:
("These exercises can be used for practice.") -> True
("Following exercises should be removed for practice.") -> False
("I use these stories in my classroom.") -> True
Click me to see the solution
Python Code Editor:
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