Add a description for the 'metadata' keyword to the docstring

Xarthisius · Xarthisius · commit a2d2c37d5500 · 2016-12-25T07:53:26.000-06:00
diff --git a/src/_png.cpp b/src/_png.cpp
@@ -114,6 +114,24 @@ const char *Py_write_png__doc__ =
     "    If not provided, libpng will try to automatically determine the\n"
     "    best filter on a line-by-line basis.\n"
     "\n"
+    "metadata : dictionary\n"
+    "    The keyword-text pairs that are stored as comments in the image.\n"
+    "    Keys must be shorter than 79 chars. The only supported encoding\n"
+    "    for both keywords and values is Latin-1 (ISO 8859-1).\n"
+    "    Examples given in the PNG Specification are:\n"
+    "    - Title: Short (one line) title or caption for image\n"
+    "    - Author: Name of image's creator\n"
+    "    - Description: Description of image (possibly long)\n"
+    "    - Copyright: Copyright notice\n"
+    "    - Creation Time: Time of original image creation\n"
+    "                     (usually RFC 1123 format, see below)\n"
+    "    - Software: Software used to create the image\n"
+    "    - Disclaimer: Legal disclaimer\n"
+    "    - Warning: Warning of nature of content\n"
+    "    - Source: Device used to create the image\n"
+    "    - Comment: Miscellaneous comment; conversion\n"
+    "               from other image format\n"
+    "\n"
     "Returns\n"
     "-------\n"
     "buffer : bytes or None\n"
