decode.py

# -*- coding: utf-8 -*-
"""Convert Unicode text into plain ASCII string."""

# for brevity the table is kept simple
CONVERSION_TABLE = {
    u"\u0394": "D",
    u"\u03b1": "a",
    u"\u03bd": "n",
    u"\u03ac": "a",
    u"\u03b7": "e"
}


def decode(string):
    """decodes unicode string to a normalised form"""
    if not isinstance(string, unicode):
        raise TypeError("unicode string is required")

    ret_string = []
    for c in string:
        code_point = ord(c)
        if code_point < 128: # ASCII
            ret_string.append(c)
        elif code_point > 983039:
            ret_string.append(c)

        heuristic_value = _get_heuristic(code_point)
        if heuristic_value is not None:
            ret_string.append(heuristic_value)
            continue

        converted_value = CONVERSION_TABLE.get(c)
        if converted_value is not None:
            ret_string.append(converted_value)
    return "".join(ret_string)


def _get_heuristic(code_point):
    """TODO(lukaszma) implement heuristic algorithms that improves conversion"""
    return None


print decode(u"\u0394\u03b1\u03bd\u03ac\u03b7")
print decode(u"Δανάη")