How to "wow" someone new to Python

[André Roberge]

On Wednesday, 21 January 2015 15:06:33 UTC-4, Chris Angelico  wrote:
> On Thu, Jan 22, 2015 at 5:20 AM, Irmen de Jong  wrote:
> > On 21-1-2015 18:59, Steve Hayes wrote:
> >
> >> 3. When I started to look at it, I found that strings could be any length and
> >> were not limited to swomething arbitrary, like 256 characters.
> >
> > Even more fun is that Python's primitive integer type (longs for older Python versions)
> > has no arbitrary limitation either.
> >
> > That amazed me at the time I discovered python :)
> 
> I hadn't worked with length-limited strings in basically forever
> (technically BASIC has a length limit, but I never ran into it; and I
> never did much with Pascal), but you're right, arbitrary-precision
> integers would have impressed me a lot more if I hadn't first known
> REXX. So... is there a way to show that off efficiently? 

How about:

 >>> def fac(n):
 ...     ans = 1
 ...     while n > 1:
 ...         ans *= n
 ...         n -= 1
 ...     return ans
 ...
 >>> a = fac(100)
 >>> a
 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000
 >>> b = fac(102)
 >>> b
 961446671503512660926865558697259548455355905059659464369444714048531715130254590603314961882364451384985595980362059157503710042865532928000000000000000000000000
 >>> b//a
 10302
 >>> b//a == 102 * 101
 True

André


Normally, any
> calculation that goes beyond 2**32 has already gone way beyond most
> humans' ability to hold the numbers in their heads.
> 
> ChrisA