Is it really worth updating all the Python syntax formatting and analysis code out there just to save one character on an operator? I don't think it's a good tradeoff.
You got:
price = 18.8
date = datetime.datetime.now()
"It's 18.80 and we are the 01/04/2016"
num, dec = str(price).split('.')
msg = ("It's "+ num + "." + dec.ljust(2, '0') +
" and we are the " + date.strftime("%m/%d/%Y") + "\n")
f.write(msg)
And it's a pain to write, or even worst, to read.
With print():
num, dec = str(price).split('.')
print("It's", num, ".", dec.ljust(2, '0'),
" and we are the ", date.strftime("%m/%d/%Y")), file=f)
If we didn't have to format the float, print() would have converted it to string for us which is nice (with + you have to call str() all the time).
With "%":
f.write("It's %.2f and we are the %s\n" % (price, date.strftime("%m/%d/%Y")))
With format():
f.write("It's {:.2f} and we are the {:%m/%d/%Y}\n".format(price, date))
With fstrings:
f.write("It's {price:.2f} and we are the {date:%m/%d/%Y}\n")
- easier / faster to type than any other versions;
- easier to read than any other versions;
- as expressive as any other versions.
The only place where you don't want fstring are for l10n.
For example, your i18n tool can extract:
"It's {price:.2f} and we are the {date:%m/%d/%Y}\n"
fr_FR: "C'est {price:.2f} et nous sommes le {date:%d/%m/%Y}\n"
All that remains is for them to work out some way of mapping in that localised string, as you can do this:
_("It's {price:.2f} and we are the {date:%m/%d/%Y}\n").format(price=price, date=date)
ISO 8601 (similar to Japanese format) is the most logical way to format dates: YYYY-MM-DD, easily sortable, not the silly way US and Europeans format their dates. ;)
If you are a fan of ISO8601 (which I am), you can then set this globally on your desktop, rather than expect the app developers / translators to choose for you.