6-regular-expressions.py

#!/usr/bin/env python

"""
Getting Started with Python:
Regular Expressions

. = any character
^ match start of line
$ match end of line
* match 0 or more repetitions
+ match 1 or more repetitions
\d match a digit {m} m times -- \d{1,2}
\w match a word character (a-z, A-Z, 0-9, _)
(|) either or
[] set of characters
[^] characters not in set i.e. [^,]*

Help: http://regexone.com/

"""

# Example text parsing
import re

text1 = 'Monday, June 4, 1997, 2:38 p.m.'
text2 = 'Thursday, March 31, 2011, 12:38 a.m.'

# match the time
time1 = re.search('\d{1,2}:\d{2} (a.m.|p.m.)', text1)
time2 = re.search('\d{1,2}:\d{2} (a.m.|p.m.)', text2)

print('The time is ' + time1.group())
print('The time is ' + time2.group())

# match the day
day1 = re.search('[^,]*', text1)
day2 = re.search('[^,]*', text2)

print('The day is ' + day1.group())
print('The day is ' + day2.group())

# match the date
date1 = re.search('\w+ \d{1,2}, \d{4}', text1)
date2 = re.search('\w+ \d{1,2}, \d{4}', text2)

print('The date is ' + date1.group())
print('The date is ' + date2.group())

# match it all
match1 = re.search('([^,]*), (\w+ \d{1,2}, \d{4}), (\d{1,2}:\d{2}) (a.m.|p.m.)', text1)
match2 = re.search('([^,]*), (\w+ \d{1,2}, \d{4}), (\d{1,2}:\d{2}) (a.m.|p.m.)', text2)

print('Day: ' + match1.group(1) + '; Date: ' + match1.group(2) +  \
      '; Time: ' + match1.group(3) + ' ' + match1.group(4))
print('Day: ' + match2.group(1) + '; Date: ' + match2.group(2) +  \
      '; Time: ' + match2.group(3) + ' ' + match2.group(4))

# Another example
form1 = 'Name: Bob Michaels'
form2 = 'Name: Pam Wells'
form3 = 'Name: Bono'

namematch1 = re.search('Name: (.*)', form1)
namematch2 = re.search('Name: (.*)', form2)
namematch3 = re.search('Name: (.*)', form3)

print(namematch1.group(1))
print(namematch2.group(1))
print(namematch3.group(1))