Update docs noting handling of s3 locations.

Author: Patrick O'Brien

doc/source/io.rst

@@ -40,8 +40,9 @@ for some advanced strategies
 
 They can take a number of arguments:
 
-  - ``filepath_or_buffer``: Either a string path to a file, or any object with a
-    ``read`` method (such as an open file or ``StringIO``).
+  - ``filepath_or_buffer``: Either a string path to a file, url
+    (including http, ftp, and s3 locations), or any object with a ``read``
+    method (such as an open file or ``StringIO``).
   - ``sep`` or ``delimiter``: A delimiter / separator to split fields
     on. `read_csv` is capable of inferring the delimiter automatically in some
     cases by "sniffing." The separator may be specified as a regular

pandas/io/parsers.py

@@ -34,7 +34,7 @@ class DateConversionError(Exception):
 Parameters
 ----------
 filepath_or_buffer : string or file handle / StringIO. The string could be
-    a URL. Valid URL schemes include http, ftp, and file. For file URLs, a host
+    a URL. Valid URL schemes include http, ftp, s3, and file. For file URLs, a host
     is expected. For instance, a local file could be
     file ://localhost/path/to/table.csv
 %s