What am I doing wrong?

[Zetlin]

Hi everyone I am writing this program that takes a string and search it for words. Those words are taken and they get "<" at the beginning and ">" at the end of the word. then it prints the string with the words and the "<, >" characters.

Here is my code:

def test():
	import re
	a = "<"
	b = ">"
	c = "Hello this is a test"
	d = re.findall(r"\bthis\b|\ba\b", c)
	e = re.split(r"\bthis\b|\ba\b", c)
	for item in d:
		y = item
		f = a+y+b
	output = f.join(re.split(r"\bthis\b|\ba\b", c))
	print output

When I run this code I get this answer:

Hello <a> is <a> test

However the answer I want is this:

Hello <this> is <a> test

Can anyone please tell me how to solve this problem? thanks in advance.

[shadwickman]

re.split breaks the string in the specified pattern, removing the parts which caused the split. There is a much simpler solution to this problem though. Just iterate the string by splitting it at each space and compare each word to a list of words you're watching for. You don't need regular expressions for this problem:

def myFunc(s):
    # break the string into a list (at each space)
    words = s.split(' ')
    # put the words we are watching for into a list
    watched = ['this', 'a']

    # loop our words and check each one
    # and add the result to our result list
    result = []
    for w in words:
        # if the word is in the watched list
        # add the carets to each side
        if w in watched:
            w = '<' + w + '>'
        # add the word to the result list
        result.append(w)

    # join our result into a string with spaces in between
    result = ' '.join(result)
    return result

My result:

>>> s = 'Hello this is a test'
>>> myFunc(s)
'Hello <this> is <a> test'

A much simpler and cleaner solution, I think :P

[Zetlin]

Yes your solution is a lot simpler, thanks