Added a block to make morphology in Czech UD more consistent.

Author: dan-zeman

udapi/block/ud/cs/fixmorpho.py

@@ -0,0 +1,21 @@
+"""
+A Czech-specific block to fix lemmas, UPOS and morphological features in UD.
+It should increase consistency across the Czech treebanks. It focuses on
+individual closed-class verbs (such as the auxiliary "být") or on entire classes
+of words (e.g. whether or not nouns should have the Polarity feature). It was
+created as part of the Hičkok project (while importing nineteenth-century Czech
+data) but it should be applicable on any other Czech treebank.
+"""
+import udapi.block.ud.fixmorpho
+import re
+
+class FixMorpho(udapi.block):
+
+    def process_node(self, node):
+        # In Czech UD, "být" is always tagged as AUX and never as VERB, regardless
+        # of the fact that it can participate in purely existential constructions
+        # where it no longer acts as a copula. Czech tagsets typically do not
+        # distinguish AUX from VERB, which means that converted data may have to
+        # be fixed.
+        if node.upos == 'VERB' and node.lemma == 'být':
+            node.upos = 'AUX'