assigning multi-line strings to variables

[Steven D'Aprano]

On Fri, 30 Apr 2010 05:41:26 +1000, Lie Ryan wrote:

> On 04/29/10 20:40, Gregory Ewing wrote:
>> Lie Ryan wrote:
>>> No, the implicit concatenation is there because Python didn't always
>>> have triple quoted string. Nowadays it's an artifact and triple quoted
>>> string is much preferred.
>> 
>> I don't agree. I often use implicit concatenation when I'm writing a
>> format string that won't fit on one source line, because it allows me
>> to fit it into the surrounding indentation structure without
>> introducing unwanted spaces into the string.
>> 
>> Both tecnhiques have their places.
>> 
>> 
> That statement should be quantified with "for large chunks of text".
> Format string is typically 2-3 lines at most, not enough to qualify as
> large chunk.

No it shouldn't. It applies equally for two lines or two hundred lines.

You seem to have missed that these are NOT equivalent:

"""abcd
efgh"""

"abcd"\
"efgh"


To avoid the ugly backslash, you can use Python's implicit line 
continuation inside brackets. This is especially handy since you often 
use brackets for function calls:

len(
"this is a very long string that won't fit"
" on a single line in the source code, but"
" must be a single line string, which is why"
" a triple-quoted string is not appropriate.")

To get the same result using triple-quoted strings, you would need to do 
this:

len(
"""this is a very long string that won't fit\
 on a single line in the source code, but\
 must be a single line string, which is why\
 a triple-quoted string is not appropriate.""")


but the second is risky, because an invisible whitespace character 
following the backslash will introduce bugs into your code:

>>> assert len(
... """abc\
... def""") == 6
Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
AssertionError




-- 
Steven