Weight expression

weight_normalization.py

def to_gram(weight, unit:str):
    if unit[-1].lower() == 't':
        weight *= 1000000 * scale_factor(unit)
        unit = 'g'
    else:
        weight *= scale_factor(unit)
        unit = 'g'
    return weight, unit


def scale_factor(unit:str):
    prefix_dict = dict(
        Y=10**24,
        Z=10**21,
        E=10**18,
        P=10**15,
        T=10**12,
        G=10**9,
        M=10**6,
        k=10**3,
        m=10**-3,
        u=10**-6,
        μ=10**-6,
        n=10**-9,
        p=10**-12,
        f=10**-15,
        a=10**-18,
        z=10**-21,
        y=10**-24,
    )

    if len(unit) == 1:
        return 1
    else:
        prefix = unit[0]
        return prefix_dict[prefix]

def weight(weight, unit='g'):
    prefix = 0
    weight, unit = to_gram(weight, unit)
    if weight < 1:
        unit = [
            'g',
            'mg',
            'μg',
            'ng',
            'pg',
        ]
        while int(weight) == 0:
            if prefix >= len(unit) - 1:
                break
            prefix += 1
            weight *= 1000
            print(int(weight))
    else:
        unit = [
            'g',
            'kg',
            't',
            'kt',
            'mt',
        ]
        while int(weight / 1000) != 0:
            if prefix >= len(unit) - 1:
                break
            prefix += 1
            weight /= 1000
    return weight, unit[prefix]