add lemma option to displacy 'dep' visualiser (#5041)

* add lemma option to displacy 'dep' visualiser

* more compact list comprehension

* add option to doc

* fix test and add lemmas to util.get_doc

* fix capital

* remove lemma from get_doc

* cleanup

spacy/displacy/__init__.py

@@ -144,10 +144,12 @@ def parse_deps(orig_doc, options={}):
             for span, tag, lemma, ent_type in spans:
                 attrs = {"tag": tag, "lemma": lemma, "ent_type": ent_type}
                 retokenizer.merge(span, attrs=attrs)
-    if options.get("fine_grained"):
-        words = [{"text": w.text, "tag": w.tag_} for w in doc]
-    else:
-        words = [{"text": w.text, "tag": w.pos_} for w in doc]
+    fine_grained = options.get("fine_grained")
+    add_lemma = options.get("add_lemma")
+    words = [{"text": w.text,
+              "tag": w.tag_ if fine_grained else w.pos_,
+              "lemma": w.lemma_ if add_lemma else None} for w in doc]
+
     arcs = []
     for word in doc:
         if word.i < word.head.i:

spacy/displacy/render.py

@@ -3,7 +3,7 @@ from __future__ import unicode_literals
 
 import uuid
 
-from .templates import TPL_DEP_SVG, TPL_DEP_WORDS, TPL_DEP_ARCS, TPL_ENTS
+from .templates import TPL_DEP_SVG, TPL_DEP_WORDS, TPL_DEP_WORDS_LEMMA, TPL_DEP_ARCS, TPL_ENTS
 from .templates import TPL_ENT, TPL_ENT_RTL, TPL_FIGURE, TPL_TITLE, TPL_PAGE
 from ..util import minify_html, escape_html, registry
 from ..errors import Errors
@@ -83,7 +83,7 @@ class DependencyRenderer(object):
         self.width = self.offset_x + len(words) * self.distance
         self.height = self.offset_y + 3 * self.word_spacing
         self.id = render_id
-        words = [self.render_word(w["text"], w["tag"], i) for i, w in enumerate(words)]
+        words = [self.render_word(w["text"], w["tag"],  w.get("lemma", None), i) for i, w in enumerate(words)]
         arcs = [
             self.render_arrow(a["label"], a["start"], a["end"], a["dir"], i)
             for i, a in enumerate(arcs)
@@ -101,7 +101,7 @@ class DependencyRenderer(object):
             lang=self.lang,
         )
 
-    def render_word(self, text, tag, i):
+    def render_word(self, text, tag, lemma, i,):
         """Render individual word.
 
         text (unicode): Word text.
@@ -114,6 +114,8 @@ class DependencyRenderer(object):
         if self.direction == "rtl":
             x = self.width - x
         html_text = escape_html(text)
+        if lemma is not None:
+            return TPL_DEP_WORDS_LEMMA.format(text=html_text, tag=tag, lemma=lemma, x=x, y=y)
         return TPL_DEP_WORDS.format(text=html_text, tag=tag, x=x, y=y)
 
     def render_arrow(self, label, start, end, direction, i):

spacy/displacy/templates.py

@@ -18,6 +18,15 @@ TPL_DEP_WORDS = """
 """
 
 
+TPL_DEP_WORDS_LEMMA = """
+<text class="displacy-token" fill="currentColor" text-anchor="middle" y="{y}">
+    <tspan class="displacy-word" fill="currentColor" x="{x}">{text}</tspan>
+    <tspan class="displacy-lemma" dy="2em" fill="currentColor" x="{x}">{lemma}</tspan>
+    <tspan class="displacy-tag" dy="2em" fill="currentColor" x="{x}">{tag}</tspan>
+</text>
+"""
+
+
 TPL_DEP_ARCS = """
 <g class="displacy-arrow">
     <path class="displacy-arc" id="arrow-{id}-{i}" stroke-width="{stroke}px" d="{arc}" fill="none" stroke="currentColor"/>

spacy/tests/test_displacy.py

@@ -31,10 +31,10 @@ def test_displacy_parse_deps(en_vocab):
     deps = displacy.parse_deps(doc)
     assert isinstance(deps, dict)
     assert deps["words"] == [
-        {"text": "This", "tag": "DET"},
-        {"text": "is", "tag": "AUX"},
-        {"text": "a", "tag": "DET"},
-        {"text": "sentence", "tag": "NOUN"},
+        {"lemma": None, "text": "This", "tag": "DET"},
+        {"lemma": None, "text": "is", "tag": "AUX"},
+        {"lemma": None, "text": "a", "tag": "DET"},
+        {"lemma": None, "text": "sentence", "tag": "NOUN"},
     ]
     assert deps["arcs"] == [
         {"start": 0, "end": 1, "label": "nsubj", "dir": "left"},

website/docs/api/top-level.md

@@ -239,6 +239,7 @@ If a setting is not present in the options, the default value will be used.
 | Name               | Type    | Description                                                                                                     | Default                 |
 | ------------------ | ------- | --------------------------------------------------------------------------------------------------------------- | ----------------------- |
 | `fine_grained`     | bool    | Use fine-grained part-of-speech tags (`Token.tag_`) instead of coarse-grained tags (`Token.pos_`).              | `False`                 |
+| `add_lemma`        | bool    | Print the lemma's in a separate row below the token texts in the `dep` visualisation.                           | `False`                 |
 | `collapse_punct`   | bool    | Attach punctuation to tokens. Can make the parse more readable, as it prevents long arcs to attach punctuation. | `True`                  |
 | `collapse_phrases` | bool    | Merge noun phrases into one token.                                                                              | `False`                 |
 | `compact`          | bool    | "Compact mode" with square arrows that takes up less space.                                                     | `False`                 |