Python has optional type annotations. There are batch tools (e.g., MyPy) 
to do type analysis and IDE's also provide help. Example:

def greeting(name: str) -> str:
     return 'Hello ' + name

I found Python to be an enormous improvement over Perl for writing the 
kinds of things I used to write in Perl, with the Perl book at my side. 
I currently make my living working on Python for microcontrollers. 
Neverthless, I am fond of type checking too, and if I were writing a 
large Python system, I would use type annotations.

I have used BCPL too, in the 70's, and we achieved some measure of type 
safety by careful naming.

Dan H.

On 8/3/23 10:19, Bakul Shah wrote:
> I have not heard such horror stories about Common Lisp (or may be I 
> have forgotten them!). My impression is that python doesn't quite have 
> the kind of {meta,}programming tools Common Lisp has. CL has been used 
> for large critical programs. Perhaps Von Rossum had more experience 
> with statically typed languages than Lisp (because -- pure speculation 
> here -- if he had used CL enough, he would never have designed python :-)
>
>> On Aug 3, 2023, at 1:32 AM, Rob Pike <robpike@gmail.com> wrote:
>>
>> I once inherited maintenance of a critical piece of infrastructure 
>> written in exquisitely well written, tested, and documented Python. I 
>> mean it, it was really really good.
>>
>> It crashed about once a week and I had to fix it over and over 
>> because in those exponentially vast combinations of paths through the 
>> code would arise yet another way to turn a string into a list, or 
>> something analogous. It was hell.
>>
>> Critical code needs static typing.
>>
>> -rob
>>
>>
>> On Thu, Aug 3, 2023 at 1:56 PM Bakul Shah <bakul@iitbombay.org> wrote:
>>
>>     python can certainly implement tail call optimization (TCO).
>>     Pretty much any language can implement TCO but for some reason
>>     people think such programs are harder to debug (and yet they
>>     don't similarly complain about loops!). The beauty of Scheme was
>>     that it *mandated* tail recursion.
>>
>>     > On Aug 2, 2023, at 8:24 PM, George Michaelson
>>     <ggm@algebras.org> wrote:
>>     >
>>     > Tail recursion not lazy eval.
>>     >
>>     > I wish words meant what I meant "inside" when I think them, not
>>     > "outside" what they mean when I write them.
>>
>