this duplicates some small ammount of fontbakery code to

avoid having to inport the whole of fontbakery as a dependency
This is very minimal so I think it is acceptable.
(issue googlefonts#3)

Lib/gftools/constants.py

@@ -0,0 +1,87 @@
+#!/usr/bin/env python2
+# Copyright 2016 The Fontbakery Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# =====================================
+# GLOBAL CONSTANTS DEFINITIONS
+
+# nameID definitions for the name table:
+NAMEID_COPYRIGHT_NOTICE = 0
+NAMEID_FONT_FAMILY_NAME = 1
+NAMEID_FONT_SUBFAMILY_NAME = 2
+NAMEID_UNIQUE_FONT_IDENTIFIER = 3
+NAMEID_FULL_FONT_NAME = 4
+NAMEID_VERSION_STRING = 5
+NAMEID_POSTSCRIPT_NAME = 6
+NAMEID_TRADEMARK = 7
+NAMEID_MANUFACTURER_NAME = 8
+NAMEID_DESIGNER = 9
+NAMEID_DESCRIPTION = 10
+NAMEID_VENDOR_URL = 11
+NAMEID_DESIGNER_URL = 12
+NAMEID_LICENSE_DESCRIPTION = 13
+NAMEID_LICENSE_INFO_URL = 14
+# Name ID 15 is RESERVED
+NAMEID_TYPOGRAPHIC_FAMILY_NAME = 16
+NAMEID_TYPOGRAPHIC_SUBFAMILY_NAME = 17
+NAMEID_COMPATIBLE_FULL_MACONLY = 18
+NAMEID_SAMPLE_TEXT = 19
+NAMEID_POSTSCRIPT_CID_NAME = 20
+NAMEID_WWS_FAMILY_NAME = 21
+NAMEID_WWS_SUBFAMILY_NAME = 22
+NAMEID_LIGHT_BACKGROUND_PALETTE = 23
+NAMEID_DARK_BACKGROUD_PALETTE = 24
+
+NAMEID_STR = {
+  NAMEID_COPYRIGHT_NOTICE: "COPYRIGHT_NOTICE",
+  NAMEID_FONT_FAMILY_NAME: "FONT_FAMILY_NAME",
+  NAMEID_FONT_SUBFAMILY_NAME: "FONT_SUBFAMILY_NAME",
+  NAMEID_UNIQUE_FONT_IDENTIFIER: "UNIQUE_FONT_IDENTIFIER",
+  NAMEID_FULL_FONT_NAME: "FULL_FONT_NAME",
+  NAMEID_VERSION_STRING: "VERSION_STRING",
+  NAMEID_POSTSCRIPT_NAME: "POSTSCRIPT_NAME",
+  NAMEID_TRADEMARK: "TRADEMARK",
+  NAMEID_MANUFACTURER_NAME: "MANUFACTURER_NAME",
+  NAMEID_DESIGNER: "DESIGNER",
+  NAMEID_DESCRIPTION: "DESCRIPTION",
+  NAMEID_VENDOR_URL: "VENDOR_URL",
+  NAMEID_DESIGNER_URL: "DESIGNER_URL",
+  NAMEID_LICENSE_DESCRIPTION: "LICENSE_DESCRIPTION",
+  NAMEID_LICENSE_INFO_URL: "LICENSE_INFO_URL",
+  NAMEID_TYPOGRAPHIC_FAMILY_NAME: "TYPOGRAPHIC_FAMILY_NAME",
+  NAMEID_TYPOGRAPHIC_SUBFAMILY_NAME: "TYPOGRAPHIC_SUBFAMILY_NAME",
+  NAMEID_COMPATIBLE_FULL_MACONLY: "COMPATIBLE_FULL_MACONLY",
+  NAMEID_SAMPLE_TEXT: "SAMPLE_TEXT",
+  NAMEID_POSTSCRIPT_CID_NAME: "POSTSCRIPT_CID_NAME",
+  NAMEID_WWS_FAMILY_NAME: "WWS_FAMILY_NAME",
+  NAMEID_WWS_SUBFAMILY_NAME: "WWS_SUBFAMILY_NAME",
+  NAMEID_LIGHT_BACKGROUND_PALETTE: "LIGHT_BACKGROUND_PALETTE",
+  NAMEID_DARK_BACKGROUD_PALETTE: "DARK_BACKGROUD_PALETTE"
+}
+
+# Platform IDs:
+PLATFORM_ID__UNICODE = 0
+PLATFORM_ID__MACINTOSH = 1
+PLATFORM_ID__ISO = 2
+PLATFORM_ID__WINDOWS = 3
+PLATFORM_ID__CUSTOM = 4
+
+PLATID_STR = {
+  PLATFORM_ID__UNICODE: "UNICODE",
+  PLATFORM_ID__MACINTOSH: "MACINTOSH",
+  PLATFORM_ID__ISO: "ISO",
+  PLATFORM_ID__WINDOWS: "WINDOWS",
+  PLATFORM_ID__CUSTOM: "CUSTOM"
+}

Lib/gftools/fonts_public.proto

@@ -0,0 +1,30 @@
+syntax = "proto2";
+
+/**
+ * Open Source'd font metadata proto formats.
+ */
+package google.fonts;
+
+option java_package = "com.google.fonts.proto";
+option java_outer_classname = "FontsPublic";
+
+message FamilyProto {
+  required string name = 1;
+  required string designer = 2;
+  required string license = 3;
+  required string category = 4;
+  required string date_added = 5;
+  repeated FontProto fonts = 6;
+  repeated string aliases = 7;
+  repeated string subsets = 8;
+};
+
+message FontProto {
+  required string name = 1;
+  required string style = 2;
+  required int32 weight = 3;
+  required string filename = 4;
+  required string post_script_name = 5;
+  required string full_name = 6;
+  optional string copyright = 7;
+};

Lib/gftools/utils.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python2
+# Copyright 2016 The Fontbakery Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+from fontTools import ttLib
+from StringIO import StringIO
+from urllib import urlopen
+from zipfile import ZipFile
+
+# =====================================
+# HELPER FUNCTIONS
+
+def download_family_from_Google_Fonts(family_name):
+    """Return a zipfile containing a font family hosted on fonts.google.com"""
+    url_prefix = 'https://fonts.google.com/download?family='
+    url = '%s%s' % (url_prefix, family_name.replace(' ', '+'))
+    return ZipFile(download_file(url))
+
+
+def download_file(url):
+    request = urlopen(url)
+    return StringIO(request.read())
+
+
+def fonts_from_zip(zipfile):
+  '''return a list of fontTools TTFonts'''
+  fonts = []
+  for file_name in zipfile.namelist():
+    if file_name.endswith(".ttf"):
+      fonts.append([file_name, ttLib.TTFont(zipfile.open(file_name))])
+  return fonts