I currently have a list of lists that looks like this:
My_List = [[This, Is, A, Sample, Text, Sentence] [This, too, is, a, sample, text] [finally, so, is, this, one]] Now what I need to do is "tag" each of these words with one of 3, in this case arbitrary, tags such as "EE", "FF", or "GG" based on which list the word is in and then reassemble them into the same order they came in. My final code would need to look like:
GG_List = [This, Sentence] FF_List = [Is, A, Text] EE_List = [Sample] My_List = [[(This, GG), (Is, FF), (A, FF), (Sample, "EE), (Text, FF), (Sentence, GG)] [*same with this sentence*] [*and this one*]] I tried this by using for loops to turn each item into a dict but the dicts then got rearranged by their tags which sadly can't happen because of the nature of this thing... the experiment needs everything to stay in the same order because eventually I need to measure the proximity of tags relative to others but only in the same sentence (list).
I thought about doing this with NLTK (which I have little experience with) but it looks like that is much more sophisticated then what I need and the tags aren't easily customized by a novice like myself.
I think this could be done by iterating through each of these items, using an if statement as I have to determine what tag they should have, and then making a tuple out of the word and its associated tag so it doesn't shift around within its list.
I've devised this.. but I can't figure out how to rebuild my list-of-lists and keep them in order :(.
for i in My_List: #For each list in the list of lists for h in i: #For each item in each list if h in GG_List: # Check for the tag MyDicts = {"GG":h for h in i} #Make Dict from tag + word Thank you so much for your help!
2 Answers
Answers 1
Putting the tags in a dictionary would work:
My_List = [['This', 'Is', 'A', 'Sample', 'Text', 'Sentence'], ['This', 'too', 'is', 'a', 'sample', 'text'], ['finally', 'so', 'is', 'this', 'one']] GG_List = ['This', 'Sentence'] FF_List = ['Is', 'A', 'Text'] EE_List = ['Sample'] zipped = zip((GG_List, FF_List, EE_List), ('GG', 'FF', 'EE')) tags = {item: tag for tag_list, tag in zipped for item in tag_list} res = [[(word, tags[word]) for word in entry if word in tags] for entry in My_List] Now:
>>> res [[('This', 'GG'), ('Is', 'FF'), ('A', 'FF'), ('Sample', 'EE'), ('Text', 'FF'), ('Sentence', 'GG')], [('This', 'GG')], []] Answers 2
Dictionary works by key-value pairs. Each key is assigned a value. To search the dictionary, you search the index by the key, e.g.
>>> d = {1:'a', 2:'b', 3:'c'} >>> d[1] 'a' In the above case, we always search the dictionary by its keys, i.e. the integers.
In the case that you want to assign the tag/label to each word, you are searching by the key word and finding the "value", i.e. the tag/label, so your dictionary would have to look something like this (assuming that the strings are words and numbers as tag/label):
>>> d = {'a':1, 'b':1, 'c':3} >>> d['a'] 1 >>> sent = 'a b c a b'.split() >>> sent ['a', 'b', 'c', 'a', 'b'] >>> [d[word] for word in sent] [1, 1, 3, 1, 1] This way the order of the tags follows the order of the words when you use a list comprehension to iterate through the words and find the appropriate tags.
So the problem comes when you have the initial dictionary indexed with the wrong way, i.e. key -> labels, value -> words, e.g.:
>>> d = {1:['a', 'd'], 2:['b', 'h'], 3:['c', 'x']} >>> [d[word] for word in sent] Traceback (most recent call last): File "<stdin>", line 1, in <module> KeyError: 'a' Then you would have to reverse your dictionary, assuming that all elements in your value lists are unique, you can do this:
>>> from collections import ChainMap >>> d = {1:['a', 'd'], 2:['b', 'h'], 3:['c', 'x']} >>> d_inv = dict(ChainMap(*[{value:key for value in values} for key, values in d.items()])) >>> d_inv {'h': 2, 'c': 3, 'a': 1, 'x': 3, 'b': 2, 'd': 1} But the caveat is that ChainMap is only available in Python3.5 (yet another reason to upgrade your Python ;P). For Python <3.5, solutions, see How do I merge a list of dicts into a single dict?.
So going back to the problem of assigning labels/tags to words, let's say we have these input:
>>> d = {1:['a', 'd'], 2:['b', 'h'], 3:['c', 'x']} >>> sent = 'a b c a b'.split() First, we invert the dictionary (assuming that there're one to one mapping for every word and its tag/label:
>>> d_inv = dict(ChainMap(*[{value:key for value in values} for key, values in d.items()])) Then, we apply the tags to the words through a list comprehension:
>>> [d_inv[word] for word in sent] [1, 2, 3, 1, 2] And for multiple sentences:
>>> sentences = ['a b c'.split(), 'h a x'.split()] >>> [[d_inv[word] for word in sent] for sent in sentences] [[1, 2, 3], [2, 1, 3]] 
0 comments:
Post a Comment