import re

# a) split 'Words, words, words.' by non-word characters.

split = re.split('\W+', 'Words, words, words.')

print(split)

# b) include the part inbetween words in the resulting list.

split = re.split('(\W+)', 'Words, words, words.')

print(split)

# c) split '0a3B9' by non-digit

split = re.split('(?i)[a-f]+', '0a3B9')

print(split)

# d) split '...words, words...' so that at beginning and end an empty

# string will be included in the result list

split = re.split('(\W+)', '...words, words...')

print(split)

# e) replace every two dashes ('--') by one ('-') and every single dash (' ') w/

# a space (' ') in the following string: 'pro----gram-files', using `re.sub` and

# a function for `repl`

programfiles = 'pro----gram-files'

res = re.sub('-{1,2}', lambda match: '-' if match.group(0) == '--' else ' ', programfiles)

print(res)

# f) extract a list of words starting w/ 'f' from this sentence: 'which foot or hand fell fastest'

fwords = re.findall(r'\bf\w+', 'which foot or hand fell fastest')

print(fwords)

# g) replace every repetition (the same word twice) w/ the word just one time: 'cat in the the drawers'

cats = 'cats in the the drawers'

neatcats = re.sub(r'\b(\w+) \1', r'\1', cats)

print(neatcats)

# h) match the first and last name of Malcolm Reynolds. Using string group id's

m = re.match('(?P<first_name>\w+) (?P<last_name>\w+)', 'Malcolm Reynald')

print(m.group('first_name', 'last_name'))

print(m.groupdict())

# i) match every two char of 'hogyha szel fujna hozzam' w/ the same group and retrieve the first group

m = re.match('(.{5})+', 'Hogyha szel fujna hozzam')

print(m.group(1))

# j) remove 'removethis' from e-mail addresses

m = re.search('(removethis)', 'tarajos.goetremovethishe@gmail.com')

print(m.string[:m.start(1)] + m.string[m.end(1):])