正则表达式从文件中返回可以用传递为参数的字母拼写的单词集（python）

Question

I have a list of words such as

name
age
abhor
apple
ape

I want to do regex on a list by passing a random set of letters such as 'apbecd'

Now all those words from the list having the set of letters must be returned.

eg: python retun_words.py apbelcdg

will return

ape
apple
age

As of now, i am able to return words based only on words match. How can I achieve the results as I have mentioned above. also if there is any other way to achieve the results instead of regex kindly let me know

Thanks in advance

Answer 1

Here, using set and returning the item is also a way, if you do not want to use regex.

string_list = ["name", "age", "abhor", "apple", "ape"]
allowed_characters = "apbelcdg"
character_set = set(allowed_charcters)
print [item for item in string_list if not set(item)-character_set]

This will give you the list of strings that adhere to the character set.

However, if regex is what you desire the most, here we go :-)

from re import match
string_list = ["name", "age", "abhor", "apple", "ape"]
allowed_characters = "apbelcdg"
print [item for item in string_list if match('[%s]*$' % (allowed_characters), item)]

Answer 2

I believe shellmode's method needs a minor fix, since it would not work for cases when the examined letter is the same as the last letter in the word, but the word itself contains letters that are not from the letter list. I believe that this code would work:

import sys
word_list = ['name', 'age', 'abhor', 'apple', 'ape']
letter_list = sys.argv[1]

for word in word_list:
    for counter,letter in enumerate(word):
        if letter not in letter_list:
            break
        if counter == len(word)-1: #reached the end of word
            print word 

Answer 3

There's no need to use regex. Following code works.

import sys
word_list = ['name', 'age', 'abhor', 'apple', 'ape']
letter_list = sys.argv[1]

for word in word_list:
    for letter in word:
        if letter not in letter_list:
            break
        elif letter == word[-1]:
            print word

Output

[root@mbp:~]# python return_words.py apbelcdg
age
apple
ape