Fraction
- Fraction(numerator=0, denominator=1)
- Fraction(number)
- Fraction(string)
This class implements rational numbers.
In the two-argument form of the constructor, Fraction(8, 6) will
produce a rational number equivalent to 4/3. Both arguments must
be Rational. The numerator defaults to 0 and the denominator
defaults to 1 so that Fraction(3) == 3 and Fraction() == 0.
Fractions can also be constructed from:
- numeric strings similar to those accepted by the
float constructor (for example, '-2.3' or '1e10')
- strings of the form '123/456'
- float and Decimal instances
- other Rational instances (including integers)© Python Software Foundation. PSF License Version 2 · Official docs ↗
Changed in 3.2, 3.9, 3.11, 3.12, 3.13, 3.14
- 3.2: The Fraction constructor now accepts float and decimal.Decimal instances.
- 3.9: The math.gcd() function is now used to normalize the numerator and denominator. math.gcd() always returns an int type. Previously, the GCD type depended on numerator and denominator.
- 3.11: Underscores are now permitted when creating a Fraction instance from a string, following PEP 515 rules.
- 3.11: Fraction implements __int__ now to satisfy typing.SupportsInt instance checks.
- 3.12: Space is allowed around the slash for string inputs: Fraction('2 / 3').
- 3.12: Fraction instances now support float-style formatting, with presentation types "e", "E", "f", "F", "g", "G" and "%"".
- 3.13: Formatting of Fraction instances without a presentation type now supports fill, alignment, sign handling, minimum width and grouping.
- 3.14: The Fraction constructor now accepts any objects with the as_integer_ratio() method.
Members of Fraction
_
- __ceil__
- math.ceil(a)
- __floor__
- math.floor(a)
- __format__
- Format this fraction according to the given format specification.
- __round__
- Rounds half toward even.
a
- as_integer_ratio
- Return a pair of integers, whose ratio is equal to the original Fraction.
d
- denominator
- Denominator of the Fraction in lowest terms.
f
- from_decimal
- Converts a finite Decimal instance to a rational number, exactly.
- from_float
- Converts a finite float to a rational number, exactly.
- from_number
- Converts a finite real number to a rational number, exactly.
i
- is_integer
- Return True if the Fraction is an integer.
l
- limit_denominator
- Closest Fraction to self with denominator at most max_denominator.
n
- numerator
- Numerator of the Fraction in lowest term.
1 Example
>>> from fractions import Fraction >>> Fraction(16, -10) Fraction(-8, 5) >>> Fraction(123) Fraction(123, 1) >>> Fraction() Fraction(0, 1) >>> Fraction('3/7') Fraction(3, 7) >>> Fraction(' -3/7 ') Fraction(-3, 7) >>> Fraction('1.414213 \t\n') Fraction(1414213, 1000000) >>> Fraction('-.125') Fraction(-1, 8) >>> Fraction('7e-6') Fraction(7, 1000000) >>> Fraction(2.25) Fraction(9, 4) >>> Fraction(1.1) Fraction(2476979795053773, 2251799813685248) >>> from decimal import Decimal >>> Fraction(Decimal('1.1')) Fraction(11, 10)
from the Python docs