Python Program-6

(6) Develop programs to learn Regular Expressions using python.

1) match() function       2) search() function

3) compile() function     4) findall() function

5) split() function

Program Code-1:match() & search() method

#Lab-6. Develop programs to learn regular expressions(re) using python.

# A Program by USING re.match() method:

""

#import re #simple structure of re.match()

#matchObject = re.match(pattern, input_str, flags=0)

""

#!/usr/bin/python

import re

line = "Cats are smarter than dogs"

matchObj = re.match( r'(.*) are (.*?) .*', line, re.M|re.I)

if matchObj:

   print ("matchObj.group() : ", matchObj.group())

   print ("matchObj.group(1) : ", matchObj.group(1))

   print ("matchObj.group(2) : ", matchObj.group(2))

else:

   print ("No match!!")

import re

pattern = '^ba...s$'

test_string = 'abyss'

result = re.match(pattern, test_string)

if result:

  print("Search is successful.")

else:

  print("Search is unsuccessful.")

#The search() function searches the string for a match, and

  #returns a Match object if there is a match.import re

txt = "The rain in Spain"

x = re.search("\s", txt)

print("The first white-space character is located in position:", x.start())

import re

txt = "The rain in Spain"

x = re.search("ai", txt)

print(x) #this will print an object

Output-1: match() & search() method

Program Code-2:compile() & findall() method

#Lab-6. Develop programs to learn regular expressions using python.

# A Program by USING re.compile() & re.findall() method:

import re

# compile() creates regular expression character class [a-e],

# which is equivalent to [abcde].

# class [abcde] will match with string with 'a', 'b', 'c', 'd', 'e'.

p = re.compile('[a-e]')

# findall() searches for the Regular Expression and return a list upon finding

print(p.findall("Hello my college is in surat gtu aicte"))

Output-2: compile() & findall() method

Program Code-3:compile() & findall() method

#Lab-6. Develop programs to learn regular expressions using python.

# A Program by USING re.compile() & re.findall() method:

import re

# \d is equivalent to [0-9].

p = re.compile('\d')

print(p.findall("I went to him at 11 A.M. on 4th July 1886"))

# \d+ will match a group on [0-9], group of one or greater size

p = re.compile('\d+')

print(p.findall("I went to him at 11 A.M. on 4th July 1886"))

Output-3: compile() & findall() method