When you try to use uuid.UUID() without arguments you get a TypeError exception saying that you can actually use an integer (while you cannot). 

Python 2.6.8 (default, Apr 26 2013, 16:24:53) 
[GCC 4.6.3] on linux2
>>> uuid.UUID()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.6/uuid.py", line 129, in __init__
    raise TypeError('need one of hex, bytes, bytes_le, fields, or int')
TypeError: need one of hex, bytes, bytes_le, fields, or int

>>> uuid.UUID(uuid.uuid4().int)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.6/uuid.py", line 131, in __init__
    hex = hex.replace('urn:', '').replace('uuid:', '')
AttributeError: 'long' object has no attribute 'replace'

So, let's check with an integer - maybe an int has 'replace'.
>>> uuid.UUID(1231231)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.6/uuid.py", line 131, in __init__
    hex = hex.replace('urn:', '').replace('uuid:', '')
AttributeError: 'int' object has no attribute 'replace'

No, it doesn't. Anyway, with a propery hex value, it works (of course!).

>>> uuid.UUID(uuid.uuid4().hex)
UUID('89b1283d-c32e-4b8a-a9e3-a699445fdd4d')

The exception message is correct. You can give an integer argument. But you have to use keyword argument.

>>> uuid.UUID(int=uuid.uuid4().int)
UUID('62ad61e5-b492-4f01-81e6-790049051c4f')

From the documentation:

 __init__(self, hex=None, bytes=None, bytes_le=None, fields=None, int=None, v
ersion=None)
 |      Create a UUID from either a string of 32 hexadecimal digits,
 |      a string of 16 bytes as the 'bytes' argument, a string of 16 bytes
 |      in little-endian order as the 'bytes_le' argument, a tuple of six
 |      integers (32-bit time_low, 16-bit time_mid, 16-bit time_hi_version,
 |      8-bit clock_seq_hi_variant, 8-bit clock_seq_low, 48-bit node) as
 |      the 'fields' argument, or a single 128-bit integer as the 'int'
 |      argument.  When a string of hex digits is given, curly braces,
 |      hyphens, and a URN prefix are all optional.  For example, these
 |      expressions all yield the same UUID:

Yeah, the first message should probably say "one of the hex, bytes, bytes_le, fields, or int arguments must be given"

I tested the patch and it seems fine. Also ran tests for uuid.py and it they passed.

New changeset f736aea929c2 by Berker Peksag in branch '3.5':
Issue #19164: Improve exception message of uuid.UUID()
https://hg.python.org/cpython/rev/f736aea929c2

New changeset e59b799df6e2 by Berker Peksag in branch 'default':
Issue #19164: Improve exception message of uuid.UUID()
https://hg.python.org/cpython/rev/e59b799df6e2

Thanks!