= Python Fractions =

'''`fractions`''' is a module supporting arithmetic with rational numbers.

<<TableOfContents>>

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== Usage ==



=== Fraction ===

A `Fraction` can be instantiated from integers, floats, strings, and [[Python/Decimal|Decimal objects]].

{{{
import fractions

fractions.Fraction(-8, 5)    #Fraction(-8, 5)

# The numerator-denominator pair can be given as separate arguments or as a formatted string
fractions.Fraction('-8/5')   #Fraction(-8, 5)

# Fraction reduces and moves signs to the numerator automatically
fractions.Fraction(16, -10)  #Fraction(-8, 5)

# Note the defaults
fractions.Fraction(123)      #Fraction(123, 1)
fractions.Fraction()         #Fraction(0, 1)
}}}

The components can be access with the `numerator` and `denominator` properties, or the `as_integer_ratio` method.

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=== Limit_Denominator ===

To approximate a fraction, use the `limit_denominator` method. It takes an integer argument that is used to construct a new `Fraction` with a denominator ''no larger'' than that integer.

{{{
import fractions

fractions.Fraction('3.1415926535897932').limit_denominator(1000)  #Fraction(355, 113)
}}}

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== See also ==

[[https://docs.python.org/3/library/fractions.html|Python fractions module documentation]]

[[https://pymotw.com/3/fractions/|Python Module of the Day article for fractions]]



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