.join() question

[drs]

why does

not automatically do

''.join([str(i) for i in lst])

? That is, is there ever a time when one does not want .join to make
everything into a string? This seems like reasonable default behavior, but
maybe I'm missing something?

-doug

 

[Terry Reedy]

why does

not automatically do

''.join([str(i) for i in lst])

? That is, is there ever a time when one does not want .join to make
everything into a string? This seems like reasonable default behavior, but
maybe I'm missing something?

If the members of lst are already str strings, this would be a waste
of time. If they are unicode strings, this would be the wrong thing
to do. Auto conversions are not Python's style.

Terry J. Reedy

 

[drs]

why does

''.join(lst)

not automatically do

''.join([str(i) for i in lst])

? That is, is there ever a time when one does not want .join to make
everything into a string? This seems like reasonable default behavior, but
maybe I'm missing something?

If the members of lst are already str strings, this would be a waste
of time. If they are unicode strings, this would be the wrong thing
to do. Auto conversions are not Python's style.

l = [u'abcde', 'fghij']
''.join(l)

u'abcdefghij'

this seems to be auto converting the non-unicode to unicode?

-d

 

[Simon Bayling]

I would risk a guess that this comes under the "explicit is better than
implicit" guideline.

''.join([str(i) for i in lst])

Explains to everyone that you know the list has some non-string things,
and you intend them to be str()'ified.

Intention-guessingly yours,
Simon.

why does

not automatically do

''.join([str(i) for i in lst])

? That is, is there ever a time when one does not want .join to make
everything into a string? This seems like reasonable default
behavior, but maybe I'm missing something?

-doug