Speaking of list-comprehension?

[Chinook]

I'm probably just getting languages mixed up, but I thought in my Python 
readings over the last couple months that I had noticed an either/or 
expression (as opposed to a bitwise or, or truth test).  Being a curious 
sort, I tried several variations of how a list comprehension *might* be 
constructed and got the results expected relative to the operators, but 
not the results I was trying to achieve.

So, is it possible to achieve what the "for loop" (below) does in a 
single list comprehension?  I don't even see a way to accomplish such in 
two list comprehensions with an intermediate result unless an index 
pattern was the criterion.

Just wondering,
Lee C

PS  I'm not suggesting it be added to the language :~)  Beyond the new 
classes and decorators (simply a convienence), I'm for KISS even to the 
extent of the much abused Case statement.


 >>> ta = [5, 15, 12, 10, 9]
 >>> for i in range(len(ta)):
...   if ta[i] >= 10:
...     ta[i] -= 10
...   else:
...     ta[i] += 10
...
 >>> ta
[15, 5, 2, 0, 19]
 >>>
 >>> [tai - 10 | tai + 10 for tai in ta if tai >= 10]
[29, 29]
 >>> [tai - 10 | tai + 10 for tai in ta]
[29, -1, -4, -2, 29]
 >>> [tai - 10 or tai + 10 for tai in ta]
[5, -5, -8, -10, 9]
 >>>