Regular Expressions purpose is to find matching string in another string. You will get either 'True' or 'False' as a response. I am not sharing here how to play tennis. My intention is if you just follow ideas, you can play tennis today.
>>> match = re.search(r'fox', 'The quick brown fox jumped...')
>>> match.group() 'fox'
Notes: The returned string is 'fox'.
>>> import re >>> re.findall(r'o', 'The quick brown fox jumped...')
['o', 'o']
Notes: It returns multiple strings.
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Python Regular Expressions
- What is a regular expression
- How does python support
- Best examples
1. What is regular expression
>>> haystack = 'My phone number is 213-867-5309.'
>>> '213-867-5309' in haystack
True
This is just a fundamental use of the regular expression. The real use of Regular Expression comes here. That is - to find if the main has any valid phone number.
Regular expressions also called regexes.
>>> import re
>>> re.search(r'fox', 'The quick brown fox jumped...')
<_sre.SRE_Match object; span=(16, 19), match='fox'>
Notes: The returned string is 'fox'.
True
This is just a fundamental use of the regular expression. The real use of Regular Expression comes here. That is - to find if the main has any valid phone number.
Regular expressions also called regexes.
2. Why do we need regx
- Data mining - to get required data if it is present are not
- Data validations - to get an answer if the received string is valid or not.
Python support
Python has its own regular expression library. That is called re. What you need to do is just import it.
>>>import re
When data matches and not matches
- If a match found, it returns the String
- If there is no match, it will return null
Example for regex
>>> re.search(r'fox', 'The quick brown fox jumped...')
<_sre.SRE_Match object; span=(16, 19), match='fox'>
Notes: The returned string is 'fox'.
Matching string
>>> match.group() 'fox'
Notes: The returned string is 'fox'.
Multiple matches
['o', 'o']
Notes: It returns multiple strings.