not in

[Neal Norwitz]

rihad wrote:
> 
> Why does python introduce new syntax with `x not in s'? Isn't it the
> same as `not (x in s)'? Same for `is not'.

Not exactly.  'not in' and 'not is' are operators, just like 'in' and 'is'.
The byte codes that are generated are slightly different.  not (...)
generates an extra byte code.

However, 'not x in s' should equal 'x not in s'.

Use whichever is clearer to you.  I prefer x not in s, because that's
how I use it in English and how I think.

Neal