It feels very close to done. Committing for now.

svn:r13

1 files changed, 190 insertions, 0 deletions

diff --git a/metaphone.py b/metaphone.py
new file mode 100644
index 0000000..99ae068
--- /dev/null
+++ b/metaphone.py
@@ -0,0 +1,190 @@
+#!/usr/bin/python2
+
+import string
+
+TRIPLES = {
+    'dge': 'j',
+    'dgi': 'j',
+    'dgy': 'j',
+    'sia': '+x',
+    'sio': '+x',
+    'tia': '+x',
+    'tio': '+x',
+    'tch': '',
+    'tha': '0',
+    'the': '0',
+    'thi': '0',
+    'tho': '0',
+    'thu': '0',
+    }
+
+DOUBLES = {
+    'ph' : 'f',
+    'sh' : 'x'
+    }
+
+SINGLETONS = {
+    'd': 't',
+    'f': 'f',
+    'j': 'j',
+    'l': 'l',
+    'm': 'm',
+    'n': 'n',
+    'r': 'r',
+    'p': 'p',
+    'q': 'k',
+    'v': 'f',
+    'x': 'ks',
+    'z': 's',
+
+
+}
+
+ALLCHARS = "".join(map(chr, range(256)))
+NONLCCHARS = "".join([c for c in ALLCHARS if not c.islower()])
+def metaphone(s):
+    s = s.lower()
+    s = s.translate(ALLCHARS, NONLCCHARS)
+    
+    if not s: return ""
+
+    # If ae, gn, kn, pn, wr then drop the first letter.
+    if s[:2] in ("ae", "gn", "kn", "pn", "wr"):
+        s = s[1:]
+
+    # Change "x" to "s"
+    if s[0] == 'x':
+        x = "s%s" % s[1:]
+
+    # Get rid of "h" in "wh".
+    if s[:2] == 'wh':
+        s = "w%s" % s[1:]
+
+    # Get rid of s from end.
+    if s[-1] == 's':
+        s = s[:-1]
+
+    result = []
+    prevLtr = ' '
+    vowelBefore = 0
+    lastChar = len(s)-1
+    for idx in range(len(s)):
+        curLtr = s[idx]
+        # If first char is a vowel, keep it.
+        if curLtr in "aeiou":
+            if idx == 0:
+                result.append(curLtr)
+            continue
+
+        # Skip double letters.
+        if idx < lastChar:
+            if curLtr == s[idx+1]:
+                continue
+
+        try:
+            r = TRIPLES[s[idx:idx+3]]
+            if r == "+x":
+                if idx > 1:
+                    result.append("x")
+                    continue
+            else:
+                result.append(r)
+                continue
+        except KeyError:
+            pass
+        try:
+            r = DOUBLES[s[idx:idx+2]]
+            result.append(r)
+            continue
+        except KeyError:
+            pass
+        try:
+            r = SINGLETONS[s[idx]]
+            result.append(r)
+            continue
+        except KeyError:
+            pass
+
+        if idx > 0:
+            prevLtr = s[idx-1]
+            vowelBefore = prevLtr in "aeiou"
+        curLtr = s[idx]
+
+        nextLtr2 = nextLtr3 = ' '
+        if idx < lastChar:
+            nextLtr = s[idx+1]
+            vowelAfter = nextLtr in "aeiou"
+            frontvAfter = nextLtr in "eiy"
+            if idx+1 < lastChar:
+                nextLtr2 = s[idx+2]
+                if idx+2 < lastChar:
+                    nextLtr3 = s[idx+3]
+        else:
+            nextLtr = ' '
+            vowelAfter = frontvAfter = 0
+
+
+        if curLtr == 'b':
+            if idx == lastChar and prevLtr == 'm':
+                pass
+            else:
+                result.append(curLtr)
+        elif curLtr == 'c':
+            # silent 'sci', 'sce, 'scy', 'sci', etc OK.
+            if not (prevLtr == 's' and frontvAfter):
+                if nextLtr in 'ia':
+                    result.append("x")
+                elif frontvAfter:
+                    result.append("s")
+                elif prevLtr == 's' and nextLtr == 'h':
+                    result.append('k')
+                elif nextLtr == 'h':
+                    if idx == 0 and nextLtr2 in "aeiou":
+                        result.append('k')
+                    else:
+                        result.append('x')
+                elif prevLtr == 'c':
+                    result.append('c')
+                else:
+                    result.append('k')
+        elif curLtr == 'g':
+            if (idx < lastChar-1) and nextLtr == 'h':
+                pass
+            elif s[idx:] == 'gned':
+                pass
+            elif s[idx:] == 'gn':
+                pass
+            elif prevLtr == 'd' and frontvAfter:
+                pass
+            else:
+                hard = (prevLtr == 'g')
+                if frontvAfter and not hard:
+                    result.append('j')
+                else:
+                    result.append('k')
+        elif curLtr == 'h':
+            if prevLtr in 'csptg':
+                pass
+            elif vowelBefore and not vowelAfter:
+                pass
+            else:
+                result.append('h')
+        elif curLtr == 'k':
+            if prevLtr != 'c': result.append('k')
+        elif curLtr in 'wy':
+            if vowelAfter:
+                result.append(curLtr)
+
+    return "".join(result)
+
+def demo(a):
+    print a, "=>", metaphone(a)
+
+print __name__ 
+if __name__ == '__main__':
+    demo("Nick. Mathewson")
+
+    demo("joe schmidt")
+    demo("Beethoven")
+
+    demo("Andrea Plaid")