Finding words that are the reverse of each other in a file
def is_reverse(word1, word2):
   if len(word1) == len(word2):
     if word1 == word2[::-1]:
       return True
return False

fin = open('List.txt')
for word1 in fin:
    word1 = word1.strip()
    word1 = word1.lower()
    for word2 in fin:
      word2 = word2.strip()
      word2 = word2.lower()
      print word1 + word2
      if is_reverse(word1, word2) is True:
             print word1 + ' is the opposite of ' + word2

def is_reverse(word1, word2):
  if len(word1) == len(word2):
      if word1 == word2[::-1]:
        return True
  return False

fin = open('List.txt')
fin2 = ['test1','test2','test3','test4','test5']
for word1 in fin:
    word1 = word1.strip()
    word1 = word1.lower()
    for word2 in fin2:
      word2 = word2.strip()
      word2 = word2.lower()
      print word1 + word2
      if is_reverse(word1, word2) is True:
             print word1 + ' is the opposite of ' + word2

def is_reverse(word1, word2):
   if len(word1) == len(word2):
     if word1 == word2[::-1]:
       return True
return False

file1 = open('List.txt')
for word1 in file1:
    word1 = word1.strip()
    word1 = word1.lower()
    file2 = open('List.txt')
    for word2 in file2:
      word2 = word2.strip()
      word2 = word2.lower()
      print word1 + word2
      if is_reverse(word1, word2):
             print word1 + ' is the opposite of ' + word2

def is_reverse(word1, word2):
    if len(word1) == len(word2):
        if word1 == word2[::-1]:
            return True
    return False

file = open('List.txt')
words = list(file)
for word1 in words:
    word1 = word1.strip()
    word1 = word1.lower()
    for word2 in words:
        word2 = word2.strip()
        word2 = word2.lower()
        print word1 + word2
        if is_reverse(word1, word2):
            print word1 + ' is the opposite of ' + word2

>>> file = open('testfile.txt')
>>> it1 = iter(file)
>>> it2 = iter(file)
>>> id(it1)
3078689064L
>>> id(it2)
3078689064L
>>> id(file)
3078689064L

>>> list = [1,2,3]
>>> it3 = iter(list)
>>> it4 = iter(list)
>>> id(it3)
3078746156L
>>> id(it4)
3078746188L
>>> id(list)
3078731244L

words = []
wordset = set(())

file = open('List.txt')
for line in file:
    word = line.strip('n')
    words.append(word)
    wordset.add(word)

for word in words:
    reversed = word[::-1]
    if reversed in wordset:
        print word + ' is the opposite of ' + reversed

def getWords(fname):
    with open(fname) as inf:
        words = list(w.strip().lower() for w in inf)
    ws = set(words)
    words = list(ws)
    words.sort()
    return words, ws

def wordsInReverse(words, wordset):
    for w in words:
        rw = w[::-1]  # reverse the string
        if rw in wordset:
            yield w,rw

def main():
    words, wordSet = getWords('List.txt')

    for w,rw in wordsInReverse(words, wordSet):
        if rw >= w:  # don't print duplicates
            print('{0} is the opposite of {1}'.format(w, rw))

if __name__=="__main__":
    main()

from itertools import chain

def main():
    words1, wordSet1 = getWords('List1.txt')
    words2, wordSet2 = getWords('List2.txt')

    for w,rw in chain(wordsInReverse(words1, wordSet2), wordsInReverse(words2, wordSet1)):
        print('{0} is the opposite of {1}'.format(w, rw))

fin1 = open("list.txt")
for word1 in fin1:
    fin2 = open("list.txt")
    for word2 in fin2:
        ...etc...

with open('palindromic.txt') as f:
    ch = f.read()
    li = [ w for w in ch.split() if len(w)>1 ]

dic ={}
pals = set([])

for line in li:
    word = line.strip().lower()
    if len(word)>1:
        if word not in dic:
            dic[word] = 1
            if word[::-1] in dic and word[::-1]!=word:
                pals.add(word)
        else:
            dic[word] += 1


for w in pals:
    print w,dic[w],'  ',w[::-1],dic[w[::-1]]