On Friday, April 18, 2014 8:46:13 PM UTC-7, Larry Hudson wrote:
> On 04/18/2014 04:14 PM, gwhite wrote:
>
> > [snip]
> > I'm not sure when a backslash continuation might be needed, or if that
> > requirement has been designed out of Python.
>
> ['they' meaning trailing backslashes]
>
> No, 'they' are still definitely in Python, but can usually be avoided.
>
> As already mentioned, strings are automatically concatenated if they are
> separated by only
> whitespace (spaces/tabs/newlines). But there is a difference between this
> concatenation and
> using a trailing backslash. For example:
>
> print('this, that, '
> 'the other')
>
> gives -> 'this, that, the other'
>
> print('this, that, \
> the other')
>
> gives -> 'this, that, the other'
>
> The leading whitespace in the second example is significant, but is ignored
> in the first.
>
> The other places you can avoid the trailing backslash is within brackets, ie.
> (), [] or {}.
> Here you can split at any 'natural' position, that is following a comma, dot
> or an operator.
>
> ['spam',
> 'eggs',
> 'bacon']
>
> gives -> ['spam', 'eggs', 'bacon']
>
> ---------
> [2 +
> 3,
> 'spam']
>
> gives -> [5, 'spam']
>
> ---------
> print('this' and
> 'that' or
> 'other')
>
> gives -> 'that'
>
> ---------
> print('{}'.
> format('spam'))
>
> gives -> 'spam'
>
> These examples are somewhat contrived, but they do show what I'm talking
> about.
>
> Of course, you can still use the trailing backslash method, but when you can
> avoid it it usually
> looks cleaner. Besides simply using either method to split long lines, it is
> often used to line
> things up, either for the appearance or for documentation. Here is a
> dictionary example of what
> I mean (and the backslash method will NOT work here):
>
> d = {1 : 'one', # Describe this key/value pair
> 2 : 'two', # Describe this one
> 3 : 'three' # Etc.
> }
>
> Play around in the interactive mode to check out how this splitting works.
Thank you, Larry. Your concise examples are nicely illustrative of the
essentials. I appreciate the explanation.
Thanks again to everyone.
If I had the time, I would become a Python addict.
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