The documentation for random.uniform() was recently updated to reflect 
the fact that it's possible for random.uniform(a, b) to produce the 
value b;  see issue 4979.

In a recent c.l.p. thread, Robert Kern suggested that 'it 
might be confusing to a user why random.random() returns values in a 
half-open interval while random.uniform() claims a closed interval';  
the thread itself confirms this potential for confusion.  See

http://mail.python.org/pipermail/python-list/2009-June/715851.html

Suggested extra wording for random.uniform, from Robert Kern:

"Due to floating point arithmetic, for some values of a and b, b may or 
may not be one of the possible generated results."