Intersection between list and first element of list of lists

I have two lists:

wordlist =  ['A', 'Aani', 'Aaron', 'Aaronic',
             'Aaronical', 'Aaronite', 'Aaronitic',
             'Aaru', 'Ab', 'Ababdeh']

and

wordlist_compound = [['A','0'], ['Aaronic','1'], ['Key','2'],
                     ['Aaronical','3'], ['Aaronite','4'], ['Yes','5']]

I would like to take the intersection of the two words and make a list that contains the word, number combination number in a third list, wordlist_final, so that wordlist_final looks like:

[['A','0'], ['Aaronic','1'], ['Aaronical','3'], ['Aaronite','4']]

My current code looks like:

wordlist_final = []
for index, word in enumerate(wordlist):
    for word_comp in wordlist_compound:
        if word[index] == wordlist_compound[index][0]:
            wordlist_final.append(wordlist_compound[index])

But I'm getting a "string index out of range error"

Solution

Your output is easily accomplished using a list comprehension:

wl=['A', 'Aani', 'Aaron', 'Aaronic', 'Aaronical', 'Aaronite', 'Aaronitic', 'Aaru', 'Ab', 'Ababdeh']
wlc=[['A','0'], ['Aaronic','1'], ['Key','2'], ['Aaronical','3'], ['Aaronite','4'], ['Yes','5']]

print [[word, i] for word,i in wlc if word in wl]    
# [['A', '0'], ['Aaronic', '1'], ['Aaronical', '3'], ['Aaronite', '4']]

Alternative LC:

print [li for li in wlc if li[0] in wl]

If you want a looping structure:

wlf = []
for word, i in wlc:
    if word in wl:
        wlf.append([word,i])

print wlf       
# [['A', '0'], ['Aaronic', '1'], ['Aaronical', '3'], ['Aaronite', '4']]

Python sequences usually don't need to be enumerated to just deal with the objects in the sequence. You usually only need to use enumerate if there is something about the index or order that is 'data' in addition to the sequence itself.

Here you are taking each element in wordlist_compound and testing membership of the word in wordlist. No need for enumeration. You also greatly simplify the task if you reverse the loops; loop over wordlist_compound rather than looping over wordlist in the outer loop as you have it. Your output is a filter of the elements in wordlist_compound; which, of course, means you can use filter too:

print filter(lambda li: li[0] in wl, wlc)
# [['A', '0'], ['Aaronic', '1'], ['Aaronical', '3'], ['Aaronite', '4']]

Cheers.