From 224bdae9962e6e252b37e68bb325795cea6000ac Mon Sep 17 00:00:00 2001
From: Matthew Honnibal <honnibal@gmail.com>
Date: Wed, 22 Oct 2014 10:17:57 +1100
Subject: [PATCH] * Add POS utilities

---
 spacy/pos_util.py | 55 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 spacy/pos_util.py

diff --git a/spacy/pos_util.py b/spacy/pos_util.py
new file mode 100644
index 000000000..5acb1fc64
--- /dev/null
+++ b/spacy/pos_util.py
@@ -0,0 +1,55 @@
+from __future__ import unicode_literals
+from . import util
+from . import tokens
+from .en import EN
+
+from .pos import Tagger
+
+
+def realign_tagged(token_rules, tagged_line, sep='/'):
+    words, pos = zip(*[token.rsplit(sep, 1) for token in tagged_line.split()])
+    positions = util.detokenize(token_rules, words)
+    aligned = []
+    for group in positions:
+        w_group = [words[i] for i in group]
+        p_group = [pos[i] for i in group]
+        aligned.append('<SEP>'.join(w_group) + sep + '_'.join(p_group))
+    return ' '.join(aligned)
+
+
+def read_tagged(detoken_rules, file_, sep='/'):
+    sentences = []
+    for line in file_:
+        line = realign_tagged(detoken_rules, line, sep=sep)
+        tokens, tags = _parse_line(line, sep)
+        assert len(tokens) == len(tags)
+        sentences.append((tokens, tags))
+    return sentences
+
+
+def _parse_line(line, sep):
+    words = []
+    tags = []
+    for token_str in line.split():
+        word, pos = token_str.rsplit(sep, 1)
+        word = word.replace('<SEP>', '')
+        subtokens = EN.tokenize(word)
+        subtags = pos.split('_')
+        while len(subtags) < len(subtokens):
+            subtags.append('NULL')
+        assert len(subtags) == len(subtokens), [t.string for t in subtokens]
+        words.append(word)
+        tags.extend([Tagger.encode_pos(pos) for pos in subtags])
+    return EN.tokenize(' '.join(words)), tags
+
+
+def get_tagdict(train_sents):
+    tagdict = {}
+    for tokens, tags in train_sents:
+        for i, tag in enumerate(tags):
+            if tag == 'NULL':
+                continue
+            word = tokens.string(i)
+            tagdict.setdefault(word, {}).setdefault(tag, 0)
+            tagdict[word][tag] += 1
+    return tagdict