How Can I Print A Float With Thousands Separators?

How can I format a decimal number so that 32757121.33 will display as 32.757.121,33?

Solution 1:

Use locale.format():

>>>import locale>>>locale.setlocale(locale.LC_ALL, 'German')
'German_Germany.1252'
>>>print(locale.format('%.2f', 32757121.33, True))
32.757.121,33

You can restrict the locale changes to the display of numeric values (when using locale.format(), locale.str() etc.) and leave other locale settings unaffected:

>>>locale.setlocale(locale.LC_NUMERIC, 'English')
'English_United States.1252'
>>>print(locale.format('%.2f', 32757121.33, True))
32,757,121.33
>>>locale.setlocale(locale.LC_NUMERIC, 'German')
'German_Germany.1252'
>>>print(locale.format('%.2f', 32757121.33, True))
32.757.121,33

Solution 2:

I have found another solution:

'{:,.2f}'.format(num).replace(".","%").replace(",",".").replace("%",",")

Solution 3:

If you can't or don't want to use locale for some reason, you can also do it with a regular expression:

import re
defsep(s, thou=",", dec="."):
    integer, decimal = s.split(".")
    integer = re.sub(r"\B(?=(?:\d{3})+$)", thou, integer)
    return integer + dec + decimal

sep() takes the string representation of a standard Python float and returns it with custom thousands and decimal separators.

>>>s = "%.2f" % 32757121.33>>>sep(s)
'32,757,121.33'
>>>sep(s, thou=".", dec=",")
'32.757.121,33'

Explanation:

\B      # Assert that we're not at the start of the number
(?=# Match at a position where it's possible to match...
 (?:#  the following regex:
  \d{3} #   3 digits
 )+     #  repeated at least once$ #  until the end of the string
)       # (thereby ensuring a number of digits divisible by 3

Solution 4:

>>>import locale>>>locale.setlocale(locale.LC_ALL, 'en_GB.UTF-8')
'en_GB.UTF-8'
>>>print(locale.format_string('%.2f', 12742126.15, True))
12,742,126.15

This sample code works for GB in a docker container.

FROM python:3.8.2-slim-buster

RUN apt-getupdate&& apt-get install -y locales && \
    sed -i -e 's/# en_GB.UTF-8 UTF-8/en_GB.UTF-8 UTF-8/'/etc/locale.gen && \
    dpkg-reconfigure --frontend=noninteractive locales

ENV LANG en_GB.UTF-8
ENV LC_ALL en_GB.UTF-8

Locales could be found by running the following command on your terminal (Linux Dirstro)

locale -a

Then a full list of locales appear:

en_AG.utf8
en_AU.utf8
...
en_GB.utf8
...