On 12/05/2019 12:31, Matthew Polack wrote:
> result = str(' Cost: ' + '${:.2f}'.format(cost))
>
> But I don't understamd what the curly brace part is actually doing:
> ..curly braces apparenly are for dictionaries...but I don't get how this is
> a dictionary..or what this {:} command is actually doing?
Curly braces inside a string are nothing to do with dictionaries or
sets(which also use them).
They are placeholders for inserted data using the format() string
method. Search the docs for string formatting, you will find a page on
the subject with many examples. (or you could read the "Simple
Sequences" topic in my tutorial - about half way down - see below)
There is another, older style of formatting that uses % characters
instead of {}. You will see both styles used regularly in Python
code. Some folks prefer one, some the other.
They are both very powerful ways of constructing output strings with
data inserted. {} and format() has a few extra tricks once you get
into advanced uses, but % style does most of the same things (and
has the advantage of being used in other languages too so you only
need to remember one style!).
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
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