[Python-ideas] The non-obvious nature of str.join (was Re: sum(...) limitation)

[Terry Reedy]

On 8/11/2014 6:23 PM, Wolfgang Maier wrote:
> On 12.08.2014 00:15, Terry Reedy wrote:

>> Nasty is a subclass of object, with no default value.  Make it a real
>> str subclass and join works fine.
>>
>> class Nasty(str):
>>      def __radd__(self, other):
>>          return other + "foo"
>>
>> print("".join(["some", "strings", "and", "one", Nasty()]))

If one runs a program with a print statement from an Idle editor,

>>  >>>
>> somestringsandone

the shell prints the >>> prompt and then the output. I copy the prompt 
as a separator.

> No, it's not,

I have been copy and pasting python code and output for over 17 years. 
You could have verified that I did so accurately here in less than a 
minute.  I keep the Idle icon pinned to my task bar and usually have a 
scratch file for experiments in its recent files list, if not already 
open, to make this sort of thing easy.

 > at least not as intended

I was talking about reality, not intentions that were not clear to me.

-- 
Terry Jan Reedy