Kind of like this question, but in reverse.
Given a string like 1, 1/2, or 1 2/3, what's the best way to convert it into a float? I'm thinking about using regexes on a case-by-case basis, but perhaps someone knows of a better way, or a pre-existing solution. I was hoping I could just use eval, but I think the 3rd case prevents that.
I tweaked James' answer a bit.
def convert_to_float(frac_str):
try:
return float(frac_str)
except ValueError:
num, denom = frac_str.split('/')
try:
leading, num = num.split(' ')
whole = float(leading)
except ValueError:
whole = 0
frac = float(num) / float(denom)
return whole - frac if whole < 0 else whole + frac
print convert_to_float('3') # 3.0
print convert_to_float('3/2') # 1.5
print convert_to_float('1 1/2') # 1.5
print convert_to_float('-1 1/2') # -1.5