需要帮助编写python中的单词查找器

Question

hi i have a question about python which im a rookie at:

i have a text file which contains a list of words (around 23000) in alphabetical order, like a small dictionary each line is a word in that textfile

i have to make a programme that asks the user for nine letters, and then the programme is supposed to rerange these letters and find all words in the textfile which match this set of nine letters

im kind of stuck in the coding of this programme, and i would like some assistance please

this is what i've done

Nian = raw_input ("Type in nine letters :")

filename = "dictionary.txt"
fil = open(filename, "r")

lines = fil.read()

tx4 = lines.strip()

a = Nian[0]    
b = Nian[1]      
c = Nian[2]       
d = Nian[3]       
e = Nian[4]    
f = Nian[5]      
g = Nian[6]    
h = Nian[7]     
i = Nian[8]

for w in lines[0:23005]:
       if a or b or c or d or e or f or g or h or i in lines:
       print w 

Answer 1

So if it's an exact match of those 9 letters, we can be a little tricky here. Instead of creating all those permutations and checking each one, merely sort the words into alphabetical order using the python built-in sorted function ( doc ) and compare the result.

The "trick" here is realizing you're looking for an anagram for those 9 letters. For Example, 'terse' and 'reset' are anagrams of each other, but if you sort them they both turn into 'eerst'.

Even if you're not looking for exact matches you can still use this trick to make optimizations.

As for the rest of the program, if you look for some basic tutorials on reading a text file with python, I'm sure you'll be able to get through the rest of it. Good luck!

Answer 2

Here is how to proceed:

1. read the file into a set() object, do not forget to remove '\\n' at the end of the lines if you use the readlines() method of the file object.
2. iterate over all permutations, using http://docs.python.org/library/itertools.html#itertools.permutations and check if one of these permutations is in your set. Maybe you have to map a tuple to a string, using the join method of str is helpful.

You know that there are 9! = 362880 9! = 362880 permutations ?

Answer 3

What pops into my mind first are sets.

This may be not the ideal solution, but should do the job:

match_letters = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i'}
for line in file:
    line = line.strip()
    line_letters = set(line)
    # test whether any letter from match_letters is in line_letters
    if line_letters & match_letters:
        print(line)

OR , if I misunderstood and you are looking for words that contain ALL nine letters:

    if line_letters >= match_letters:
        print(line)

OR , if you are looking for words that contain ONLY those nine letters:

    if line_letters <= match_letters:
        print(line)