Python - Parse float string to an integer

Question

I want to convert a string like "0.75" into 3/4. Do python has any builtin function for this.

I know i can convert it using float("0.75") to get a float value. But I need only integer number without loosing resolution.

I can write a function like multiplying it by 100, so I will get 75/100, but still how to evaulate to 3/4. Any idea would be much appreciated.

Tim Pietzcker · Accepted Answer · 2013-02-13 14:17:35Z

4

>>> from fractions import Fraction
>>> Fraction(0.75)
Fraction(3, 4)

See the docs.

One caveat: Non-binary fractions (i.e. fractions derived from floating point numbers that cannot be represented accurately in binary, like 0.9) may yield surprising results unless you pass the string representation of the float:

>>> Fraction(0.9)
Fraction(8106479329266893, 9007199254740992)
>>> Fraction("0.9")
Fraction(9, 10)

answered Feb 13, 2013 at 12:09

Tim Pietzcker

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Comments

eumiro · Accepted Answer · 2013-02-13 12:09:05Z

3

Python has the fractions module.

>>> import fractions
>>> fractions.Fraction('0.75')
Fraction(3, 4)

answered Feb 13, 2013 at 12:09

eumiro

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