Regular Expressions

[a-zA-Z]+
matches one or more ascii letters
[A-Z][a-z]*
matches zero or more ascii letters
p[aeiou]{,2}t
matches a word consisting of p followed by up to 2 vowels, followed by t
\d+(\.\d+)?
matches a digit followed possibly by a full stop and more digits
([^aeiou][aeiou][^aeiou])*
Matches zero or more CVC combinations
\w+|[^\w\s]+

Extract Dates

Input: "My birthday is on 25/12/1990 and my friend's is on 01/01/2000."
Output: ['25/12/1990', '01/01/2000']

Normalize Spaces

Input: "This   is   an example    sentence."
Output: This is an example sentence.

Mask Digits

Input: My phone number is 123-456-7890.
Year: 2023
About four o'clock.

Output: My phone number is 123-456-7890. Year: 2023 About four o'clock.

Mask Digits

Input: "My birthday is on 25/12/1990 and my friend's is on 01/01/2000."
Output: My birthday is on ##/##/#### and my friend's is on ##/##/####.

Count Word Occurences

Input: "Pen, pineapple, apple-pen and pineapple-pen", "apple"
Output: 1
Input: PPAP, "apple"
Output: 5
In:
 
I have a pen
I have an apple
Ah
Apple pen
I have a pen
I have pineapple
Ah
Pineapple pen
Apple pen
Pineapple pen
Ah
Pen Pie Pineapple Apple Pen
Pen Pie Pineapple Apple Pen

Trying:
    count_word_occurrences("This is an example. This is fun!", "this")
Expecting:
    2
ok
Trying:
    count_word_occurrences("apple pie and pineapple", "apple")
Expecting:
    1
ok
Trying:
    count_word_occurrences("Nothing to see here.", "banana")
Expecting:
    0
ok
Trying:
    count_word_occurrences("Cat, caterpillar, and the cat.", "cat")
Expecting:
    2
ok
Trying:
    extract_dates("My birthday is on 25/12/1990 and my friend's is on 01/01/2000.")
Expecting:
    ['25/12/1990', '01/01/2000']
ok
Trying:
    extract_dates("No dates here.")
Expecting:
    []
ok
Trying:
    mask_digits("My phone number is 123-456-7890.")
Expecting:
    'My phone number is ###-###-####.'
ok
Trying:
    mask_digits("Year: 2023")
Expecting:
    'Year: ####'
ok
Trying:
    mask_digits("No digits here.")
Expecting:
    'No digits here.'
ok
Trying:
    normalize_spaces("This   is   an example    sentence.")
Expecting:
    'This is an example sentence.'
ok
Trying:
    normalize_spaces("  Hello   world!  ")
Expecting:
    'Hello world!'
ok
1 items had no tests:
    __main__
4 items passed all tests:
   4 tests in __main__.count_word_occurrences
   2 tests in __main__.extract_dates
   3 tests in __main__.mask_digits
   2 tests in __main__.normalize_spaces
11 tests in 5 items.
11 passed and 0 failed.
Test passed.