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I am also active in many other area and still look after a lot of web sites - you can find an index ((here))
Regular Expression Overview
String Handling example from a Well House Consultants training course
More on String Handling [link]

This example is described in the following article(s):
   • Regular Expressions in Python - [link]

Source code: reggie.py Module: Y108

Regular Expressions in Python - A summary

1. Literal: Exact match
        3 A @ \+ \.

2. Character Group: Any 1 character from a set
        [aeiouy] [A-JP-Z7] [^#*/] .
        \s \d \w \S \D \W

3. Counts: Number of time the preceeding item
        {2,6} {4,} {3}
        ? + *
3a - Sparse counts:
        {2,6}? {4,}?
        ?? +? *?

4. Anchor: zero width assertions
        ^ $ \b \B

5. Grouping: for counts, for alternation, for capture
        ( ..... )
        (?: ..... ) (no capture)

6. Alternation:


import re

# A simple example - an email address as "something@something"

rob = re.compile(r'((\S+)@(\S+))')
say = """My email address is graham@wellho.net and
        info@wellhousemanor.co.uk will reach me but I have others"""
result = rob.findall(say)

# Sparse v Greedy;
# First part of example is greedy and returns one long match

html = "<h1>The <b>strong</b> coffee</h1>"
tag = r"<(.+)>"
tagex = re.compile(tag)
result = tagex.findall(html)

# Second part of example is sparse and return each tag separately
propertag = r"<(.+?)>"
tagex = re.compile(propertag)
result = tagex.findall(html)

# Split returns just the bits BETWEEN the matches
# PLUS "interesting bits" which are captured

result = tagex.split(html)

# USA postcode such as CA 96543 - 7653
# REMEMBER - use a raw string if you have things like \b!

# re.VERBOSE allows me to put spaces and comments into a regex

zipper = re.compile(r'''
        (\d{5}) # the vital bit
stuff = zipper.findall("""kaskasdjk CA 96543 - 7653 asjajsdjk
        and 66432 but not 66552 nor 77666-7799""")

""" --------------------- results ----------------------

WomanWithCat:y108 grahamellis$ python2 reggie.py
[('graham@wellho.net', 'graham', 'wellho.net'), ('info@wellhousemanor.co.uk', 'info', 'wellhousemanor.co.uk')]
['h1>The <b>strong</b> coffee</h1']
['h1', 'b', '/b', '/h1']
['', 'h1', 'The ', 'b', 'strong', '/b', ' coffee', '/h1', '']
[('96543', '7653'), ('66432', ''), ('66552', ''), ('77666', '7799')]
WomanWithCat:y108 grahamellis$ python3 reggie.py
[('graham@wellho.net', 'graham', 'wellho.net'), ('info@wellhousemanor.co.uk', 'info', 'wellhousemanor.co.uk')]
['h1>The <b>strong</b> coffee</h1']
['h1', 'b', '/b', '/h1']
['', 'h1', 'The ', 'b', 'strong', '/b', ' coffee', '/h1', '']
[('96543', '7653'), ('66432', ''), ('66552', ''), ('77666', '7799')]
WomanWithCat:y108 grahamellis$


Learn about this subject
This module and example are covered on the following public courses:
 * Learning to program in Python
 * Python Programming
 * Intermediate Python
Also available on on site courses for larger groups

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Other Examples
This example comes from our "String Handling" training module. You'll find a description of the topic and some other closely related examples on the "String Handling" module index page.

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