[Python-ideas] Implicit string literal concatenation considered harmful?

[Jonathan Eunice]

Implicit line concatenation is one of those rare places where Python
turns an oddly blind eye to the "Explicit is better than implicit"
rule it otherwise loves.

I can't speak to how much inconvenience/breakage it would cause,
but deprecating it would seem to increase the language's "coherence"
with--or at least, adherence to--its principles.

But I have no real stake in it; I seldom if ever use the construct.

I prefer a trick I learned in Perl: Using a "here document" cleanup
function. This allows multi-line literal strings to be stated in a
program, at whatever level of indentation is appropriate for code
clarity, and the indentation to be automatically removed. For
example, using [textdata](https://pypi.python.org/pypi/textdata):

    from textdata import *

    data = lines("""
        There was an old woman who lived in a shoe.
        She had so many children, she didn't know what to do;
    """)

will result in:

    ['There was an old woman who lived in a shoe.',
     "She had so many children, she didn't know what to do;"]

This is dedented, but also had some blank lines at the start
and end removed (the blanks make Python formatting look good,
but might gunk up subsequent processing). `lines` can also
do what implicit concatenation does:

    data = lines(join=True, text="""
        this
        that
    """)

gives a purely concatenated result:

    'thisthat'

The `join` kwarg, given a string, will join on that string. Some
edge-case options aside, being able to state indented literal strings
without fussing with line-by-line quoting is the jewel.

Especially if Python's implicit line concatenation is going to be
deprecated, you might consider adding an "ease of multi-line string
specification" function like `lines` to the standard library (in
`textwrap`?) to ease the passing.