How to convert a measurement displayed in an architectural format to a floating point?

Question

I have a database that was created and is used by an architecture firm. All measurements are stored in a format like this: 15-3/4" and 12' 6-3/4".

Is there a way to convert these types of measurements into floating point in Python? Or is there a library out there that provides this functionality?

Likewise, how would you convert from a floating point to the above format?

Answer 1

Depending on how regular the patterns are, you can use str.partition to do the parsing:

def architectural_to_float(text):
    ''' Convert architectural measurements to inches.

        >>> for text in """15-3/4",12' 6-3/4",3/4",3/4',15',15",15.5'""".split(','):
        ...     print text.ljust(10), '-->', architectural_to_float(text)
        ...
        15-3/4"    --> 15.75
        12' 6-3/4" --> 150.75
        3/4"       --> 0.75
        3/4'       --> 9.0
        15'        --> 180.0
        15"        --> 15.0
        15.5'      --> 186.0

    '''
    # See http://stackoverflow.com/questions/8675714
    text = text.replace('"', '').replace(' ', '')
    feet, sep, inches = text.rpartition("'")
    floatfeet, sep, fracfeet = feet.rpartition('-')
    feetnum, sep, feetdenom = fracfeet.partition('/')
    feet = float(floatfeet or 0) + float(feetnum or 0) / float(feetdenom or 1)
    floatinches, sep, fracinches = inches.rpartition('-')
    inchesnum, sep, inchesdenom = fracinches.partition('/')
    inches = float(floatinches or 0) + float(inchesnum or 0) / float(inchesdenom or 1)
    return feet * 12.0 + inches