On 03/21/2014 09:57 PM, Jerry Hill wrote:
On Fri, Mar 21, 2014 at 3:25 PM, Gary Engstrom <gwengst...@yahoo.com> wrote:
I am trying to understand function fibc code line a,b = b, a + b and would
like to see it written line by line
without combining multiply assignment. If possible. I sort of follow the
right to left evaluation of the other code.
Sure. a,b = b, a+b is equivalent to:
new_a = b
new_b = a + b
a = new_a
b = new_b
del new_a
del new_b
That is, we first evaluate everything on the right hand side of the
equals sign, then assign those values to a and b. Then we get rid of
the temporary variables, since the original statement didn't leave any
temporary variable floating around.
In other words, it is like
a = b ; b = a+b
performed *in parallel*. Another way to write it is:
old_a = a
a = b
b = old_a + b
d
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