Add convert command

spacy/__main__.py

@@ -10,12 +10,13 @@ from spacy.cli import info as cli_info
 from spacy.cli import package as cli_package
 from spacy.cli import train as cli_train
 from spacy.cli import model as cli_model
+from spacy.cli import convert as cli_convert
 
 
 class CLI(object):
     """Command-line interface for spaCy"""
 
-    commands = ('download', 'link', 'info', 'package', 'train', 'model')
+    commands = ('download', 'link', 'info', 'package', 'train', 'model', 'convert')
 
     @plac.annotations(
         model=("model to download (shortcut or model name)", "positional", None, str),
@@ -110,6 +111,20 @@ class CLI(object):
 
         cli_model(lang, model_dir, freqs_data, clusters_data, vectors_data)
 
+    @plac.annotations(
+        input_file=("input file", "positional", None, str),
+        output_dir=("output directory for converted file", "positional", None, str),
+        n_sents=("Number of sentences per doc", "option", "n", float),
+        morphology=("Enable appending morphology to tags", "flag", "m", bool)
+    )
+    def convert(self, input_file, output_dir, n_sents=10, morphology=False):
+        """
+        Convert files into JSON format for use with train command and other
+        experiment management functions.
+        """
+
+        cli_convert(input_file, output_dir, n_sents, morphology)
+
 
     def __missing__(self, name):
         print("\n   Command %r does not exist."

spacy/cli/__init__.py

@@ -4,3 +4,4 @@ from .link import link
 from .package import package
 from .train import train, train_config
 from .model import model
+from .convert import convert

spacy/cli/convert.py

@@ -0,0 +1,37 @@
+# coding: utf8
+from __future__ import unicode_literals, division, print_function
+
+import io
+from pathlib import Path, PurePosixPath
+
+from .converters import conllu2json
+from .. import util
+
+
+# Converters are matched by file extension. To add a converter, add a new entry
+# to this dict with the file extension mapped to the converter function imported
+# from /converters.
+
+CONVERTERS = {
+    '.conllu': conllu2json
+}
+
+
+def convert(input_file, output_dir, *args):
+    input_path = Path(input_file)
+    output_path = Path(output_dir)
+    check_dirs(input_path, output_path)
+    file_ext = input_path.suffix
+
+    if file_ext in CONVERTERS:
+        CONVERTERS[file_ext](input_path, output_path, *args)
+    else:
+        util.sys_exit("Can't find converter for {}".format(input_path.parts[-1]),
+                      title="Unknown format")
+
+
+def check_dirs(input_file, output_path):
+    if not input_file.exists():
+        util.sys_exit(input_file.as_posix(), title="Input file not found")
+    if not output_path.exists():
+        util.sys_exit(output_path.as_posix(), title="Output directory not found")