Is there an existing mapping from utf8 to latin-1? Python

Question

Is there a mapping from utf8 to normalized non-accented letters in both latin-1 and utf8?

I have been getting errors such as:

UnicodeEncodeError: 'latin-1' codec can't encode character u'\u010d' in position 4: ordinal not in range(256)

And I am solving each one of these error manually by doing the following code. Is there a better way to do this?:

def prehunpos(sentence):
    sentence = sentence.replace(u'\u2018',"'") # left single quote mark
    sentence = sentence.replace(u'\u2019',"'") # right single quote mark
    sentence = sentence.replace(u'\u201C','"') # left double quote mark
    sentence = sentence.replace(u'\u201D','"') # right double quote mark
    sentence = sentence.replace(u'\u2010',"-") # hyphen
    sentence = sentence.replace(u'\u2011',"-") # non-break hyphen
    sentence = sentence.replace(u'\u2012',"-") # figure dash
    sentence = sentence.replace(u'\u2013',"-") # dash
    sentence = sentence.replace(u'\u2014',"-") # some sorta dash
    sentence = sentence.replace(u'\u2015',"-") # long dash
    sentence = sentence.replace(u'\u2017',"_") # double underscore
    sentence = sentence.replace(u'\u2014',"-") # some sorta dash
    sentence = sentence.replace(u'\u2016',"|") # long dash
    sentence = sentence.replace(u'\u2024',"...") # ...
    sentence = sentence.replace(u'\u2025',"...") # ...
    sentence = sentence.replace(u'\u2026',"...") # ...
    sentence = sentence.replace("\xce\x9d\xce\x91\xce\xa4\xce\x9f",u'NATO') # NATO

    sentence = sentence.replace(u'\u0391',"A") # Greek Capital Alpha
    sentence = sentence.replace(u'\u0392',"B") # Greek Capital Beta
    #sentence = sentence.replace(u'\u0393',"") # Greek Capital Gamma
    #sentence = sentence.replace(u'\u0394',"") # Greek Capital Delta
    sentence = sentence.replace(u'\u0395',"E") # Greek Capital Epsilon
    sentence = sentence.replace(u'\u0396',"Z") # Greek Capital Zeta
    sentence = sentence.replace(u'\u0397',"H") # Greek Capital Eta
    #sentence = sentence.replace(u'\u0398',"") # Greek Capital Theta
    sentence = sentence.replace(u'\u0399',"I") # Greek Capital Iota
    sentence = sentence.replace(u'\u039a',"K") # Greek Capital Kappa
    #sentence = sentence.replace(u'\u039b',"") # Greek Capital Lambda
    sentence = sentence.replace(u'\u039c',"M") # Greek Capital Mu
    sentence = sentence.replace(u'\u039d',"N") # Greek Capital Nu
    #sentence = sentence.replace(u'\u039e',"") # Greek Capital Xi
    sentence = sentence.replace(u'\u039f',"O") # Greek Capital Omicron
    sentence = sentence.replace(u'\u03a1',"P") # Greek Capital Rho
    #sentence = sentence.replace(u'\u03a3',"") # Greek Capital Sigma
    sentence = sentence.replace(u'\u03a4',"T") # Greek Capital Tau
    sentence = sentence.replace(u'\u03a5',"Y") # Greek Capital Upsilon
    #ssentence = sentence.replace(u'\u03a6',"") # Greek Capital Phi
    sentence = sentence.replace(u'\u03a7',"T") # Greek Capital Chi
    #sentence = sentence.replace(u'\u03a8',"") # Greek Capital Psi
    #sentence = sentence.replace(u'\u03a9',"") # Greek Capital Omega

    sentence = sentence.replace(u'\u03b1',"a") # Greek small alpha
    sentence = sentence.replace(u'\u03b2',"b") # Greek small beta
    #sentence = sentence.replace(u'\u03b3',"") # Greek small gamma
    #sentence = sentence.replace(u'\u03b4',"") # Greek small delta
    sentence = sentence.replace(u'\u03b5',"e") # Greek small epsilon
    #sentence = sentence.replace(u'\u03b6',"") # Greek small zeta
    #sentence = sentence.replace(u'\u03b7',"") # Greek small eta
    #sentence = sentence.replace(u'\u03b8',"") # Greek small thetha
    sentence = sentence.replace(u'\u03b9',"i") # Greek small iota
    sentence = sentence.replace(u'\u03ba',"k") # Greek small kappa
    #sentence = sentence.replace(u'\u03bb',"") # Greek small lamda
    sentence = sentence.replace(u'\u03bc',"u") # Greek small mu
    sentence = sentence.replace(u'\u03bd',"v") # Greek small nu
    #sentence = sentence.replace(u'\u03be',"") # Greek small xi
    sentence = sentence.replace(u'\u03bf',"o") # Greek small omicron
    #sentence = sentence.replace(u'\u03c0',"") # Greek small pi
    sentence = sentence.replace(u'\u03c1',"p") # Greek small rho
    sentence = sentence.replace(u'\u03c2',"c") # Greek small final sigma
    #sentence = sentence.replace(u'\u03c3',"") # Greek small sigma
    sentence = sentence.replace(u'\u03c4',"t") # Greek small tau
    sentence = sentence.replace(u'\u03c5',"u") # Greek small upsilon
    #sentence = sentence.replace(u'\u03c6',"") # Greek small phi
    sentence = sentence.replace(u'\u03c7',"x") # Greek small chi
    sentence = sentence.replace(u'\u03c8',"x") # Greek small psi
    sentence = sentence.replace(u'\u03c9',"w") # Greek small omega


    sentence = sentence.replace(u'\u0103',"a") # Latin a with breve
    sentence = sentence.replace(u'\u0107',"c") # Latin c with acute
    sentence = sentence.replace(u'\u010d',"c") # Latin c with caron
    sentence = sentence.replace(u'\u0161',"s") # Lation s with caron

    return sentence.strip()

Answer 1

If you need a general means to transform non-Latin scripts into Latin, an ICU transform is the best choice. There is a Python wrapper for ICU, PyICU (http://pypi.python.org/pypi/PyICU). However, if you are only targeting a single script (looks like you are specifically interested in Greek?), a mapping table is the quickest solution. Although you could write it more concisely:

#!/usr/bin/python
# -*- coding: utf-8 -*-

greek_to_latin = {u"Α": u"A", u"Β": u"B", u"Γ": u"G"}  # ...
latin_string = "".join(greek_to_latin[c] for c in greek_string)

You might also check out the unicodedata module which has a means to identify the category of a character, to identify non-ASCII punctuation symbols.