>>> '{0:,}'.format(1000000)
'1,000,000'

>>> import locale
>>> locale.setlocale(locale.LC_ALL, '')
'en_AU.utf8'
>>> locale.format('%d', 1000000, 1)
'1,000,000'

>>> import locale
>>> locale.setlocale(locale.LC_ALL, 'de_DE.utf-8')
'de_DE.utf-8'
>>> locale.format('%d', 1000000, 1)
'1.000.000'

>>> format(1123000,',d')
'1,123,000'

> my_float = 123456789.123456789
> "{:0,.2f}".format(my_float)
'123,456,789.12'

[[fill]align][sign][#][0][width][,][.precision][type]

>>> from itertools import zip_longest
>>> num = "1000000"
>>> sep = "."
>>> places = 3
>>> args = [iter(num[::-1])] * places
>>> sep.join("".join(x) for x in zip_longest(*args, fillvalue=""))[::-1]
'1.000.000'

i=1234567890
s=str(i)
str1=""
s1=[elm for elm in s]
if len(s1)%3==0:
    for i in range(0,len(s1)-3,3):
        str1+=s1[i]+s1[i+1]+s1[i+2]+"."
    str1+=s1[i]+s1[i+1]+s1[i+2]
else:
    rem=len(s1)%3
    for i in range(rem):
        str1+=s1[i]
    for i in range(rem,len(s1)-1,3):
        str1+="."+s1[i]+s1[i+1]+s1[i+2]

print str1

1.234.567.890

ax=plt.gca()
ax.get_xaxis().set_major_formatter(matplotlib.ticker.FuncFormatter(lambda x, loc: locale.format('%d', x, 1)))