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Fraction literals should support underscores in numbers and whitespace around numbers #96432
Description
Activity
See also #88512
this should be made to work:
Fraction('31_415_925_535 / 10_000_000_000')Agreed on the underscores, both for readability and for consistency with
int.+1 to allowing whitespace around the slash, too.
I don't agree with the slippery slope argument in #88512 (comment).
complexhas all sorts of oddities both in parsing and printing, and I don't see any need for those to limit what seem like fairly natural enhancements forFraction.FTR, underscore support was added previously in #26422
To make fraction literals more readable, this should be made to work:
Fraction('31_415_925_535 / 10_000_000_000')PEP 515 – Underscores in Numeric Literals are well supported in all numeric types except for fractions. This works:
1_234andDecimal('1_234'). However, this is not accepted:Fraction('1_234').Like decimals and ints, fractions support leading and trailing whitespace for string inputs:
int(' 123 '),Decimal(' 123.4 '), andFraction(' 123/100 '). What is still needed is support for optional whitespace around the forward slash:Fraction('355 / 113'). This particular example came up when using the Fraction module to teach math to kids and where the string literal was obtained from callinginput().Side note: If you write
print(355/113)in your code, Black will reformat it toprint(355 / 113). Because of this, I expect that adults will also develop a preference for writing fractions with whitespace around the slash.