the rules .txt file is text only
you need to read through that text file and parse the lines for the variables yourself
I'd do something kind of like this

(just the juicy parts, all this needs wrapping

code:

---

#initalise the dictionary
variables = {} #create dictionary to hold text variables
read through rules.txt
split each line on " "
for each word in the split array, see if it starts with a "<"
if it does then
    variables{word} = ""


#actual program stuff
    convert input string to lower case and remove all punctuation
    split input string into array on space  (use split function)
    call it user_input

    open rules.txt
    building = True
    while building = true
        read line from file
        split line into array on |  #convert input line into request and response, one sets variables one gets them
        request = split(inputline[0]," ")  # split lines into words
        response = split(inputline[1]," ")
        wordnum = 0
        comparing = True
        match = False
        while  comparing #this part deals with the request
              if userinput[currentword] == request[currentword]
                   print "matched %s" % (currentword)
              elseif the first letter of word is "<"   # then its a variable
                   if variables[word] = "" then
                        variable[word] = input[currentword] #set the variable to the thing the user entered
               else
                    print "It didnt match"
                    building = False
       if current_word = len(user_input) then
            print "Matched the whole string"
            building = False
            match = True
       current_word +=1

---

The python challenge is over i ended on 189/200 couldn't get that last one I was so close but ran out of time

code:

---

# section that finds the variables in the rule file
import re

variables = {} #create dictionary to hold text variables
for line in open("rules.txt"):
    line = line.rstrip('\n')
    stripped_text = "" 
    for c in line:
        if c in '!"#$%&\'()*+,-./:;=?@[\\]^_`{}~':
            c = ""
        stripped_text += c
    words = stripped_text.split(" ")
    for word in words:
        m = re.findall('<.*?>', word)
        m = ''.join(m)
        if m not in variables:
            variables[m] = ''

# user_input loop

running = True
while running  == True:
    user_input = raw_input(">")
    if user_input == "":
        break
    words = user_input.split(" ")
    z = 0
    answer = []
    ended = False

    # this is the compairing and output section
    for line in open("rules.txt"):
        built = False
        matched = 0
        while not built :
            line = line.rstrip('\n')
            split = line.split(" | ")
            request = split[0].split(" ")
            response = split[1].split(" ")
            compaired = False
            matched = 0
            currentword = 0
            while not compaired :
                m = re.findall('<.*?>', request[currentword])
                m = ''.join(m)
                if words[currentword] == request[currentword]:
                    if m != '':
                        variables[m] = words[currentword]
                    matched += 1
                elif m != '':
                    variables[m] = words[currentword]
                    matched += 1
# this is where it checks wether the whole thing matched and if the varialbes are not empty it also makes the final answer
                if currentword == len(words)-1:
                    built = True
                    compaired = True
                    broken = False
                    if matched == len(request):
                        answer = []
                        for word in response:
                            if not broken:
                                m = re.findall('<.*?>', word)
                                m = ''.join(m)
                                if m == '':
                                    answer.append(word)
                                else:
                                    if variables[m] == '':
                                        broken = True
                                        compaired = True
                                    else:
                                        h = re.sub('<.*?>',variables[m], word)
                                        answer.append(h)       
                        print ' '.join(answer)
                        z = 1
                        built = True
                        compaired = True
                    built = True
                    compaired = True
                elif currentword == len(request)-1 or len(request) != len(words):
                    built = True
                    compaired = True
                else:
                    currentword += 1
    if z != 1:
        print "Please go on"
         

---