Implements issue #9951: Adds a hex() method to bytes, bytearray, & memoryview.

Also updates a few internal implementations of the same thing to use the
new built-in code.

Contributed by Arnon Yaari.

2 files changed, 40 insertions, 0 deletions

diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index 26ff309..2c66fca 100644
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -2289,6 +2289,19 @@ the bytes type has an additional class method to read data in that format:
    >>> bytes.fromhex('2Ef0 F1f2  ')
    b'.\xf0\xf1\xf2'
 
+A reverse conversion function exists to transform a bytes object into its
+hexadecimal representation.
+
+.. method:: bytes.hex()
+
+   Return a string object containing two hexadecimal digits for each
+   byte in the instance.
+
+   >>> b'\xf0\xf1\xf2'.hex()
+   'f0f1f2'
+
+   .. versionadded:: 3.5
+
 Since bytes objects are sequences of integers (akin to a tuple), for a bytes
 object *b*, ``b[0]`` will be an integer, while ``b[0:1]`` will be a bytes
 object of length 1.  (This contrasts with text strings, where both indexing
@@ -2344,6 +2357,19 @@ the bytearray type has an additional class method to read data in that format:
    >>> bytearray.fromhex('2Ef0 F1f2  ')
    bytearray(b'.\xf0\xf1\xf2')
 
+A reverse conversion function exists to transform a bytearray object into its
+hexadecimal representation.
+
+.. method:: bytearray.hex()
+
+   Return a string object containing two hexadecimal digits for each
+   byte in the instance.
+
+   >>> bytearray(b'\xf0\xf1\xf2').hex()
+   'f0f1f2'
+
+   .. versionadded:: 3.5
+
 Since bytearray objects are sequences of integers (akin to a list), for a
 bytearray object *b*, ``b[0]`` will be an integer, while ``b[0:1]`` will be
 a bytearray object of length 1.  (This contrasts with text strings, where
@@ -3458,6 +3484,17 @@ copying.
       supports all format strings, including those that are not in
       :mod:`struct` module syntax.
 
+   .. method:: hex()
+
+      Return a string object containing two hexadecimal digits for each
+      byte in the buffer. ::
+
+         >>> m = memoryview(b"abc")
+         >>> m.hex()
+         '616263'
+
+      .. versionadded:: 3.5
+
    .. method:: tolist()
 
       Return the data in the buffer as a list of elements. ::
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
index f364317..da7c5bb 100644
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -80,6 +80,9 @@ New built-in features:
 
 * ``bytes % args``, ``bytearray % args``: :pep:`461` - Adding ``%`` formatting
   to bytes and bytearray
+* ``b'\xf0\x9f\x90\x8d'.hex()``, ``bytearray(b'\xf0\x9f\x90\x8d').hex()``,
+  ``memoryview(b'\xf0\x9f\x90\x8d').hex()``: :issue:`9951` - A ``hex`` method
+  has been added to bytes, bytearray, and memoryview.
 
 Implementation improvements: