#!/usr/bin/python

import re


sequence = "ACGTacgtAcgtttatatatatatatatactctctctcgcagcagtgtcagtgtcgtacgstgcagtsgbackschtgcccatatatatatatatatatatatatatatatatatatattaatactatctdtatsta".upper()


# ex. 0
#
# search for a stop codon
#

print sequence.find('TAG')
print sequence.find('TGA')
print sequence.find('TAA')
print sequence[119:122]

# ex. 1
#
# search for the first occurance ta followed by any other character
#

a = re.search('TA.',sequence)
print a.group(0)

# ex. 2
#
# search for all occurances of ta followed by any other character
#

a = re.findall('TA.',sequence)
print a

# ex. 3
#
# same as example 1, but using a (fast) pattern object
#

a = re.compile('TA.')
b = a.search(sequence)
print b.group(0)

# ex. 4
#
# same as example 2, but using a (fast) pattern object
#

a = re.compile('TA.')
b = a.findall(sequence)
print b

# ex. 5
#
# find g followed by t or b
#

a = re.findall('G[T|B]',sequence)
print a