I need to convert some strings to float. Most of them are only numbers but some of them have letters too. The regular float() function throws an error.
a='56.78'
b='56.78 ab'
float(a) >> 56.78
float(b) >> ValueError: invalid literal for float()
One solution is to check for the presence of other characters than numbers, but I was wondering if there is some built-in or other short function which gives:
magicfloat(a) >> 56.78
magicfloat(b) >> 56.78
You can try stripping letters from your input:
from string import ascii_lowercase
b='56.78 ab'
float(b.strip(ascii_lowercase))
b='56.78 ab#$', this does not work.
use a regex
import re
def magicfloat(input):
numbers = re.findall(r"[-+]?[0-9]*\.?[0-9]+", input)
# TODO: Decide what to do if you got more then one number in your string
if numbers:
return float(numbers[0])
return None
a=magicfloat('56.78')
b=magicfloat('56.78 ab')
print a
print b
output:
56.78
56.78
Short answer: No.
There is no built-in function that can accomplish this.
Longish answer: Yes:
One thing you can do is go through each character in the string to check if it is a digit or a period and work with it from there:
def magicfloat(var):
temp = list(var)
temp = [char for char in temp if char.isdigit() or char == '.']
var = "".join(temp)
return var
As such:
>>> magicfloat('56.78 ab')
'56.78'
>>> magicfloat('56.78')
'56.78'
>>> magicfloat('56.78ashdusaid')
'56.78'
>>>