Add spacy.link module to link model directories to shortcuts

spacy/link.py

@@ -0,0 +1,75 @@
+# coding: utf8
+from __future__ import unicode_literals
+
+import io
+import os
+import sys
+import pip
+import site
+import plac
+from . import util
+
+
+@plac.annotations(
+    origin=("Package name or path to model", "positional", None, str),
+    link_name=("Name of link", "positional", None, str),
+    force=("Force overwriting existing link", "flag", "f", bool)
+)
+def link(origin, link_name, force=False):
+    """Create a symlink for models within the spacy/data directory. Accepts
+    either the name of a pip package, or the local path to the model data
+    directory. Linking models allows loading them via spacy.load(link_name)."""
+
+    if is_package(origin):
+        package_path = site.getsitepackages()[0]
+        meta = get_meta(package_path, origin)
+        data_dir = origin + '-' + meta['version']
+        model_path = os.path.join(package_path, origin, data_dir)
+        symlink(model_path, link_name, force)
+    else:
+        symlink(origin, link_name, force)
+
+
+def symlink(model_path, link_name, force):
+    if not os.path.isdir(model_path):
+        exit("The data should be located in {p}".format(p=model_path),
+                title="Can't locate model data")
+
+    data_path = str(util.get_data_path())
+    link_path = os.path.join(os.path.abspath(__file__ + '/../../'), data_path, link_name)
+
+    if os.path.isdir(link_path):
+        if force:
+            os.unlink(link_path)
+        else:
+            exit("To overwrite an existing link, use the --force flag.",
+                 title="Link {l} already exists".format(l=link_name))
+
+    os.symlink(model_path, link_path)
+    util.print_msg("{a} --> {b}".format(a=model_path, b=link_path),
+                   "You can now load the model via spacy.load('{l}').".format(l=link_name),
+                   title="Linking successful")
+
+def get_meta(package_path, package):
+    meta = util.parse_package_meta(package_path, package)
+    if not meta:
+        exit()
+    return meta
+
+
+def is_package(origin):
+    packages = pip.get_installed_distributions()
+    for package in packages:
+        if package.project_name.replace('-', '_') == origin:
+            return True
+    return False
+
+
+def exit(*messages, **kwargs):
+    if messages:
+        util.print_msg(*messages, **kwargs)
+    sys.exit(0)
+
+
+if __name__ == '__main__':
+    plac.call(link)