add missing fetch script for the face dataset

Author: ogrisel

.gitignore

@@ -13,3 +13,5 @@ data/movie_reviews/poldata.README.2.0
 data/languages/paragraphs
 data/languages/short_paragraphs
 data/languages/html
+
+data/labeled_faces_wild/lfw_preprocessed/

data/labeled_faces_wild/fetch_data.py

@@ -0,0 +1,27 @@
+"""Simple script to fetch a numpy version of the LFW data
+
+Original dataset and credits available at:
+
+  http://vis-www.cs.umass.edu/lfw/
+
+"""
+import os
+import urllib2
+
+URL = "https://downloads.sourceforge.net/project/scikit-learn/data/lfw_preprocessed.tar.gz"
+ARCHIVE_NAME = "lfw_preprocessed.tar.gz"
+FOLDER_NAME = "lfw_preprocessed"
+
+if not os.path.exists(FOLDER_NAME):
+    if not os.path.exists(ARCHIVE_NAME):
+        print "Downloading data, please Wait (58.8MB)..."
+        print URL
+        opener = urllib2.urlopen(URL)
+        open(ARCHIVE_NAME, 'wb').write(opener.read())
+        print
+
+    import tarfile
+    print "Decompressiong the archive: " + ARCHIVE_NAME
+    tarfile.open(ARCHIVE_NAME, "r:gz").extractall()
+    os.remove(ARCHIVE_NAME)
+