#!/usr/bin/python

import re
def fix_floats(json, decimals=2, quote='"'):
    pattern = r'^((?:(?:"(?:\\.|[^\\"])*?")|[^"])*?)(-?\d+\.\d{'+str(decimals)+'}\d+)'
    pattern = re.sub('"', quote, pattern) 
    fmt = "%%.%df" % decimals
    n = 1
    while n:
        json, n = re.subn(pattern, lambda m: m.group(1)+(fmt % float(m.group(2))), json)
    return json

json = '[23.670000000000002, "\\"\\\\", 23.969999999999999, "23.870000000000001"]'
print(json)
print(fix_floats(json))

pyon = repr([23.67, "\"\'\\", "23.969999999999999", 23.87])
print(pyon)
print(fix_floats(pyon, decimals=3, quote="'"))