How to do it...

1. Import the re module:

>>> import re

2. Then, match a pattern that is not at the start of the string:

>>> re.search(r'LOG', 'SOME LOGS')
<_sre.SRE_Match object; span=(5, 8), match='LOG'>

3. Match a pattern that is only at the start of the string. Note the ^ character:

>>> re.search(r'^LOG', 'LOGS')
<_sre.SRE_Match object; span=(0, 3), match='LOG'>
>>> re.search(r'^LOG', 'SOME LOGS')
>>>

4. Match a pattern only at the end of the string. Note the $ character:

>>> re.search(r'LOG$', 'SOME LOG')
<_sre.SRE_Match object; span=(5, 8), match='LOG'>
>>> re.search(r'LOG$', 'SOME LOGS')
>>>

5. Match the word 'thing' (not excluding things), but not something or anything. Note the \b at the start of the second pattern:

>>> STRING = 'something in the things she shows me'
>>> match = re.search(r'thing', STRING)
>>> STRING[:match.start()], STRING[match.start():match.end()], STRING[match.end():]
('some', 'thing', ' in the things she shows me')
>>> match = re.search(r'\bthing', STRING)
>>> STRING[:match.start()], STRING[match.start():match.end()], STRING[match.end():]
('something in the ', 'thing', 's she shows me')

6. Match a pattern that's only numbers and dashes (for example, a phone number). Retrieve the matched string:

>>> re.search(r'[0123456789-]+', 'the phone number is 1234-567-890')
<_sre.SRE_Match object; span=(20, 32), match='1234-567-890'>
>>> re.search(r'[0123456789-]+', 'the phone number is 1234-567-890').group()
'1234-567-890'

7. Match an email address naively:

>>> re.search(r'\S+@\S+', 'my email is email.123@test.com').group()
'email.123@test.com'