diff -r e548ab4ce71d Doc/library/http.client.rst
--- a/Doc/library/http.client.rst	Mon Feb 09 19:49:00 2015 +0000
+++ b/Doc/library/http.client.rst	Fri Feb 13 07:45:43 2015 -0800
@@ -212,8 +212,10 @@
    contents of the file is sent; this file object should support ``fileno()``
    and ``read()`` methods. The header Content-Length is automatically set to
    the length of the file as reported by stat. The *body* argument may also be
-   an iterable and Content-Length header should be explicitly provided when the
-   body is an iterable.
+   an iterable. If the iterable is a tuple or list, the Content-Length will
+   automatically be set if not already supplied in the request headers.
+   In all other iterable cases, the Content-Length header should be explicitly
+   provided.
 
    The *headers* argument should be a mapping of extra HTTP
    headers to send with the request.
@@ -221,6 +223,10 @@
    .. versionadded:: 3.2
       *body* can now be an iterable.
 
+   .. versionadded:: 3.5
+      The Content-Length header will be set when *body* is a list or tuple.
+
+
 .. method:: HTTPConnection.getresponse()
 
    Should be called after a request is sent to get the response from the server.
diff -r e548ab4ce71d Lib/http/client.py
--- a/Lib/http/client.py	Mon Feb 09 19:49:00 2015 +0000
+++ b/Lib/http/client.py	Fri Feb 13 07:45:43 2015 -0800
@@ -836,11 +836,19 @@
                     datablock = datablock.encode("iso-8859-1")
                 self.sock.sendall(datablock)
             return
+
+        if isinstance(data, str):
+            # RFC 2616 Section 3.7.1 says that text default has a
+            # default charset of iso-8859-1.
+            data = data.encode('iso-8859-1')
+
         try:
             self.sock.sendall(data)
         except TypeError:
             if isinstance(data, collections.Iterable):
                 for d in data:
+                    if hasattr(d, 'encode'):
+                        d = d.encode('iso-8859-1')
                     self.sock.sendall(d)
             else:
                 raise TypeError("data should be a bytes-like object "
@@ -1031,20 +1039,25 @@
 
     def _set_content_length(self, body):
         # Set the content-length based on the body.
-        thelen = None
-        try:
-            thelen = str(len(body))
-        except TypeError as te:
-            # If this is a file-like object, try to
-            # fstat its file descriptor
+        size = None
+        if isinstance(body, (list, tuple)):
+            # the body will either be already encoded or will be latin-1
+            # encoded when being sent. as latin-1 and ascii strings are of
+            # equal size, there isn't a need to make a distinction here.
+            size = sum(len(line) for line in body)
+        else:
             try:
-                thelen = str(os.fstat(body.fileno()).st_size)
-            except (AttributeError, OSError):
-                # Don't send a length if this failed
-                if self.debuglevel > 0: print("Cannot stat!!")
+                size = len(body)
+            except TypeError:
+                try:
+                    size = os.fstat(body.fileno()).st_size
+                except (AttributeError, OSError):
+                    if self.debuglevel > 0:
+                        print("Cannot stat!!")
+                    size = None
 
-        if thelen is not None:
-            self.putheader('Content-Length', thelen)
+        if size is not None:
+            self.putheader('Content-Length', size)
 
     def _send_request(self, method, url, body, headers):
         # Honor explicitly requested Host: and Accept-Encoding: headers.
@@ -1061,10 +1074,6 @@
             self._set_content_length(body)
         for hdr, value in headers.items():
             self.putheader(hdr, value)
-        if isinstance(body, str):
-            # RFC 2616 Section 3.7.1 says that text default has a
-            # default charset of iso-8859-1.
-            body = body.encode('iso-8859-1')
         self.endheaders(body)
 
     def getresponse(self):
diff -r e548ab4ce71d Lib/test/test_httplib.py
--- a/Lib/test/test_httplib.py	Mon Feb 09 19:49:00 2015 +0000
+++ b/Lib/test/test_httplib.py	Fri Feb 13 07:45:43 2015 -0800
@@ -1161,7 +1161,6 @@
     def setUp(self):
         self.conn = client.HTTPConnection('example.com')
         self.conn.sock = self.sock = FakeSocket("")
-        self.conn.sock = self.sock
 
     def get_headers_and_fp(self):
         f = io.BytesIO(self.sock.data)
@@ -1226,6 +1225,25 @@
             self.assertEqual("5", message.get("content-length"))
             self.assertEqual(b'body\xc1', f.read())
 
+    def test_list_body(self):
+        cases = (
+            ([b'foo', b'bar'], b'foobar'),
+            ((b'foo', b'bar'), b'foobar'),
+            ((b'foo', 'bar'), b'foobar'),
+            ([b'foo', 'bar'], b'foobar'),
+        )
+        for body, expected in cases:
+            with self.subTest(body):
+                self.conn = client.HTTPConnection('example.com')
+                self.conn.sock = self.sock = FakeSocket('')
+
+                self.conn.request('PUT', '/url', body)
+                msg, f = self.get_headers_and_fp()
+                self.assertNotIn('Content-Type', msg)
+                self.assertIsNone(msg.get_charset())
+                self.assertEqual(len(expected), int(msg.get('content-length')))
+                self.assertEqual(expected, f.read())
+
 
 class HTTPResponseTest(TestCase):