type conversion - How can I convert a string with dot and comma into a float in Python

110
votes

How can I convert a string like 123,456.908 to float 123456.908 in Python?

9
pythontype-conversion
The proper way to do this is to use the locale module - everything else is just a very nasty hack that will get you into trouble in the future. - Nick Bastin
The proper localeway is also a very good way to shoot you in the foot if you plan to use your program on several operating systems (like Windows and flavors of Linux), which have different locale formats or even might need you to install a locale that supports your chosen format... - 576i

9 Answers

152
votes

Just remove the , with replace():

float("123,456.908".replace(',',''))
162
votes

... Or instead of treating the commas as garbage to be filtered out, we could treat the overall string as a localized formatting of the float, and use the localization services:

from locale import atof, setlocale, LC_NUMERIC
setlocale(LC_NUMERIC, '') # set to your default locale; for me this is
# 'English_Canada.1252'. Or you could explicitly specify a locale in which floats
# are formatted the way that you describe, if that's not how your locale works :)
atof('123,456') # 123456.0
# To demonstrate, let's explicitly try a locale in which the comma is a
# decimal point:
setlocale(LC_NUMERIC, 'French_Canada.1252')
atof('123,456') # 123.456
9
votes

If you don't know the locale and you want to parse any kind of number, use this parseNumber(text) function. It is not perfect but take into account most cases :

>>> parseNumber("a 125,00 €")
125
>>> parseNumber("100.000,000")
100000
>>> parseNumber("100 000,000")
100000
>>> parseNumber("100,000,000")
100000000
>>> parseNumber("100 000 000")
100000000
>>> parseNumber("100.001 001")
100.001
>>> parseNumber("$.3")
0.3
>>> parseNumber(".003")
0.003
>>> parseNumber(".003 55")
0.003
>>> parseNumber("3 005")
3005
>>> parseNumber("1.190,00 €")
1190
>>> parseNumber("1190,00 €")
1190
>>> parseNumber("1,190.00 €")
1190
>>> parseNumber("$1190.00")
1190
>>> parseNumber("$1 190.99")
1190.99
>>> parseNumber("1 000 000.3")
1000000.3
>>> parseNumber("1 0002,1.2")
10002.1
>>> parseNumber("")

>>> parseNumber(None)

>>> parseNumber(1)
1
>>> parseNumber(1.1)
1.1
>>> parseNumber("rrr1,.2o")
1
>>> parseNumber("rrr ,.o")

>>> parseNumber("rrr1rrr")
1
7
votes

If you have a comma as decimals separator and the dot as thousands separator, you can do:

s = s.replace('.','').replace(',','.')
number = float(s)

Hope it will help

6
votes

What about this?

 my_string = "123,456.908"
 commas_removed = my_string.replace(',', '') # remove comma separation
 my_float = float(commas_removed) # turn from string to float.

In short:

my_float = float(my_string.replace(',', ''))
3
votes
s =  "123,456.908"
print float(s.replace(',', ''))
2
votes

Here's a simple way I wrote up for you. :)

>>> number = '123,456,789.908'.replace(',', '') # '123456789.908'
>>> float(number)
123456789.908
1
votes

Just replace, with replace().

f = float("123,456.908".replace(',','')) print(type(f)

type() will show you that it has converted into a float

1
votes

Better solution for different currency formats:

def text_currency_to_float(text):
  t = text
  dot_pos = t.rfind('.')
  comma_pos = t.rfind(',')
  if comma_pos > dot_pos:
    t = t.replace(".", "")
    t = t.replace(",", ".")
  else:
    t = t.replace(",", "")

  return(float(t))