python human readable large numbers [duplicate]

Answer 1

(Edit: Can't believe I am updating my answer in 2019 and again in 2020! This proves that the next phrase of human evolution is to share knowledge over the internet!)

With Python2.7+ or v3 you just use the "," option in your string formatting:

>>> "{:,}".format(100000000)
'100,000,000'

See PEP 378: Format Specifier for Thousands Separator for more info:

http://www.python.org/dev/peps/pep-0378/

With Python3.6+ you can also use the "_" format:

>>> "{:_}".format(100000000)
'100_000_000'

See PEP 515 for details:

https://www.python.org/dev/peps/pep-0515/

Added in 2014: These days I have the following shell function:

human_readable_numbers () {
    python2.7 -c "print('{:,}').format($1)"
}

So I don't have to squint my eyes on big numbers.

Stop here unless you are unfortunate enough to be working with pre-2.7 code or environment without Python 2.7 when you read this...

You can also do that with locale:

import locale
locale.setlocale(locale.LC_ALL, 'en_US')
locale.format('%d', 2**32, grouping=True)   # returns '4,294,967,296'

Hope this helps!