From d3ffe4ca63bc2e581e30f115b74377b1f3f4c753 Mon Sep 17 00:00:00 2001
From: Matthew Honnibal <honnibal+gh@gmail.com>
Date: Thu, 27 Aug 2020 18:56:58 +0200
Subject: [PATCH] Fix error when tagger was initialized with no labels

---
 spacy/pipeline/tagger.pyx | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/spacy/pipeline/tagger.pyx b/spacy/pipeline/tagger.pyx
index 2255a585a..af24bf336 100644
--- a/spacy/pipeline/tagger.pyx
+++ b/spacy/pipeline/tagger.pyx
@@ -286,7 +286,10 @@ class Tagger(Pipe):
         for tag in sorted(tags):
             self.add_label(tag)
         self.set_output(len(self.labels))
-        self.model.initialize(X=doc_sample)
+        if self.labels:
+            self.model.initialize(X=doc_sample)
+        else:
+            self.model.initialize()
         if sgd is None:
             sgd = self.create_optimizer()
         return sgd