Personally, I don't particularly like the way you have to put multiline
strings on the far left (rather than aligned with the rest of the scope)
to avoid getting spaces at the beginning of each line. I find it makes
it more difficult to see where the scope of the class/method/etc.
actually ends, especially if there are multiple such strings. It's not
too bad for strings defined at the module level (outer scope) though,
and of course for docstrings the extra spaces at the beginning of each
line don't matter.
However, rather than using "+" to join strings as in your examples
(which, as you suggest, is probably less efficient), I tend to use
string literal concatenation which I gather is more efficient (treated
as a single string at compile-time rather than joining separate strings
at run-time). See
<https://docs.python.org/3/reference/lexical_analysis.html#string-literal-concatenation>.
For example:
HelpText = ("Left click: Open spam\n"
"Shift + Left click: Cook spam\n"
"Right click: Crack egg\n"
"Shift + Right click: Fry egg\n")
The downside is having to put an explicit "\n" at the end of each line,
but to me that's not as bad as having to align the content to the far left.
Getting a bit more on topic, use of backslashes in strings is a bit
different to backslashes for line continuation anyway. You could almost
think of "\
(newline)" in a multiline string as being like an escape sequence
meaning "don't actually put a newline character in the string here", in
a similar way to "\n" meaning "put a newline character here" and "\t"
meaning "put a tab character here".
Mark.
avi.e.gr...@gmail.com wrote:
Good example, Rob, of how some people make what I consider RELIGIOUS edicts
that one can easily violate if one wishes and it makes lots of sense in your
example.
Let me extend that. The goal was to store a character string consisting of
multiple lines when printed that are all left-aligned. Had you written:
HelpText = """
Left click: Open spam
...
Shift + Right click: Fry egg
"""
Then it would begin with an extra carriage return you did not want. Your
example also ends with a carriage return because you closed the quotes on
another line, so a \ on the last line of text (or moving the quotes to the end
of the line) would be a way of avoiding that.
Consider some alternatives I have seen that are in a sense ugly and may involve
extra work for the interpreter unless it is byte compiled once.
def someFunc():
HelpText =
"Left click: Open spam" + "\n" +
"Shift + Left click: Cook spam" + "\n" +
...
Or the variant of:
HelpText = "Left click: Open spam\n"
HelpText += " Shift + Left click: Cook spam\n"
...
Or perhaps just dumping the multi-line text into a file beforehand and reading
that into a string!
def someFunc():
The backslash is not looking like such a bad idea! LOL!
-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail....@python.org> On
Behalf Of Rob Cliffe via Python-list
Sent: Wednesday, February 22, 2023 2:08 PM
To: python-list@python.org
Subject: Re: Line continuation and comments
On 22/02/2023 15:23, Paul Bryan wrote:
Adding to this, there should be no reason now in recent versions of
Python to ever use line continuation. Black goes so far as to state
"backslashes are bad and should never be used":
https://black.readthedocs.io/en/stable/the_black_code_style/future_sty
le.html#using-backslashes-for-with-statements
def someFunc():
HelpText = """\
Left click: Open spam
Shift + Left click: Cook spam
Right click: Crack egg
Shift + Right click: Fry egg
"""
The initial backslash aligns the first line with the others (in a fixed font of
course).
Best wishes
Rob Cliffe
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