Question

How can I convert strings which can denote decimal or rational numbers to floats

>>> ['0.1234', '1/2'] ['0.1234', '1/2'] 

I’d want [0.1234, 0.5].

eval is what I was thinking but no luck:

>>> eval('1/2') 0 

Answer 1

I’d parse the string if conversion fails:

>>> def convert(s):     try:         return float(s)     except ValueError:         num, denom = s.split('/')         return float(num) / float(denom) ...  >>> convert('0.1234') 0.1234  >>> convert('1/2') 0.5 

Generally using eval is a bad idea, since it’s a security risk. Especially if the string being evaluated came from outside the system.