diff -r eb26255e11f1 Lib/http/client.py
--- a/Lib/http/client.py	Wed Jan 28 11:06:04 2015 +0200
+++ b/Lib/http/client.py	Thu Jan 29 17:11:42 2015 -0800
@@ -1028,20 +1028,21 @@
 
     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
+        if isinstance(body, list) or isinstance(body, tuple):
+            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.
diff -r eb26255e11f1 Lib/test/test_httplib.py
--- a/Lib/test/test_httplib.py	Wed Jan 28 11:06:04 2015 +0200
+++ b/Lib/test/test_httplib.py	Thu Jan 29 17:11:42 2015 -0800
@@ -53,6 +53,8 @@
         self.port = port
 
     def sendall(self, data):
+        if isinstance(data, str):
+            data = data.encode('ascii')
         self.sendall_calls += 1
         self.data += data
 
@@ -1161,7 +1163,6 @@
     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 +1227,24 @@
             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', 'bar'], b'foobar'),
+            ((b'foo', b'bar'), b'foobar'),
+            ((b'foo', 'bar'), b'foobar'),
+        )
+        for body, expected in cases:
+            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.assertEqual('text/plain', msg.get_content_type())
+            self.assertIsNone(msg.get_charset())
+            self.assertEqual(str(len(expected)), msg.get('content-length'))
+            self.assertEqual(expected, f.read())
+
 
 class HTTPResponseTest(TestCase):