peplin · December 13, 2010 20:03 · Dec 13, 2010 · Dec 13, 2010 · Apr 11, 2009 · Apr 11, 2009
diff --git a/baseconv.py b/baseconv.py
@@ -56,13 +56,6 @@ def to_decimal(self, s):
             decoded = -decoded
         return decoded
 
-bin = BaseConverter('01')
-hexconv = BaseConverter('0123456789ABCDEF')
-base32 = Base32Converter()
-base62 = BaseConverter(
-    'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz'
-)
-
 class Base32Converter(BaseConverter):
     """
     http://www.crockford.com/wrmg/base32.html
@@ -79,6 +72,13 @@ def __init__(self):
     def to_decimal(self, s):
         return super(Base32Converter, self).to_decimal(s.lower())
 
+bin = BaseConverter('01')
+hexconv = BaseConverter('0123456789ABCDEF')
+base32 = Base32Converter()
+base62 = BaseConverter(
+    'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz'
+)
+
 if __name__ == '__main__':
     import doctest
     doctest.testmod()
diff --git a/__init__.py b/__init__.py
diff --git a/baseconv.py b/baseconv.py
@@ -1,6 +1,8 @@
 """
 Convert numbers from base 10 integers to base X strings and back again.
 
+Original: http://www.djangosnippets.org/snippets/1431/
+
 Sample usage:
 
 >>> base20 = BaseConverter('0123456789abcdefghij')
@@ -11,53 +13,72 @@
 """
 
 class BaseConverter(object):
-    decimal_digits = "0123456789"
+    decode_mapping = {}
 
     def __init__(self, digits):
         self.digits = digits
+        self.length = len(digits)
 
     def from_decimal(self, i):
-        return self.convert(i, self.decimal_digits, self.digits)
-
-    def to_decimal(self, s):
-        return int(self.convert(s, self.digits, self.decimal_digits))
-
-    def convert(number, fromdigits, todigits):
-        # Based on http://code.activestate.com/recipes/111286/
-        if str(number)[0] == '-':
-            number = str(number)[1:]
-            neg = 1
+        if i < 0:
+            i, neg = -i, 1
         else:
             neg = 0
-
-        # make an integer out of the number
-        x = 0
-        for digit in str(number):
-           x = x * len(fromdigits) + fromdigits.index(digit)
+        enc = ''
+        while i >= self.length:
+            i, mod = divmod(i, self.length)
+            enc = self.digits[mod] + enc
+        enc = self.digits[i] + enc
+        if neg:
+            enc = '-' + enc
+        return enc
 
-        # create the result in base 'len(todigits)'
-        if x == 0:
-            res = todigits[0]
+    def to_decimal(self, s):
+        if self.decode_mapping:
+            new = ''
+            for digit in s:
+                if digit in self.decode_mapping:
+                    new += self.decode_mapping[digit]
+                else:
+                    new += digit
+            s = new
+        if str(s)[0] == '-':
+            s, neg = str(s)[1:], 1
         else:
-            res = ""
-            while x > 0:
-                digit = x % len(todigits)
-                res = todigits[digit] + res
-                x = int(x / len(todigits))
-            if neg:
-                res = '-' + res
-        return res
-    convert = staticmethod(convert)
+            neg = 0
+        decoded = 0
+        multi = 1
+        while len(s) > 0:
+            decoded += multi * self.digits.index(s[-1:])
+            multi = multi * self.length
+            s = s[:-1]
+        if neg:
+            decoded = -decoded
+        return decoded
 
 bin = BaseConverter('01')
 hexconv = BaseConverter('0123456789ABCDEF')
+base32 = Base32Converter()
 base62 = BaseConverter(
     'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz'
 )
 
-if __name__ == '__main__':
-    nums = [-10 ** 10, 10 ** 10] + range(-100, 100)
-    for convertor in [bin, hex, base62]:
-        for i in nums:
-            assert i == bin.to_decimal(bin.from_decimal(i)), '%s failed' % i
+class Base32Converter(BaseConverter):
+    """
+    http://www.crockford.com/wrmg/base32.html
+    """
+    decode_mapping = {
+        'o': '0',
+        'i': '1',
+        'l': '1',
+    }
+
+    def __init__(self):
+        super(Base32Converter, self).__init__('0123456789abcdefghjkmnpqrstvwxyz')
+
+    def to_decimal(self, s):
+        return super(Base32Converter, self).to_decimal(s.lower())
 
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()
diff --git a/baseconv.py b/baseconv.py
@@ -3,14 +3,14 @@
 
 Sample usage:
 
->>> base20 = BaseConvertor('0123456789abcdefghij')
+>>> base20 = BaseConverter('0123456789abcdefghij')
 >>> base20.from_decimal(1234)
 '31e'
 >>> base20.from_decimal('31e')
 1234
 """
 
-class BaseConvertor(object):
+class BaseConverter(object):
     decimal_digits = "0123456789"
 
     def __init__(self, digits):
@@ -49,9 +49,9 @@ def convert(number, fromdigits, todigits):
         return res
     convert = staticmethod(convert)
 
-bin = BaseConvertor('01')
-hexconv = BaseConvertor('0123456789ABCDEF')
-base62 = BaseConvertor(
+bin = BaseConverter('01')
+hexconv = BaseConverter('0123456789ABCDEF')
+base62 = BaseConverter(
     'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz'
 )
 

diff --git a/baseconv.py b/baseconv.py
@@ -0,0 +1,63 @@
+"""
+Convert numbers from base 10 integers to base X strings and back again.
+
+Sample usage:
+
+>>> base20 = BaseConvertor('0123456789abcdefghij')
+>>> base20.from_decimal(1234)
+'31e'
+>>> base20.from_decimal('31e')
+1234
+"""
+
+class BaseConvertor(object):
+    decimal_digits = "0123456789"
+
+    def __init__(self, digits):
+        self.digits = digits
+
+    def from_decimal(self, i):
+        return self.convert(i, self.decimal_digits, self.digits)
+
+    def to_decimal(self, s):
+        return int(self.convert(s, self.digits, self.decimal_digits))
+
+    def convert(number, fromdigits, todigits):
+        # Based on http://code.activestate.com/recipes/111286/
+        if str(number)[0] == '-':
+            number = str(number)[1:]
+            neg = 1
+        else:
+            neg = 0
+
+        # make an integer out of the number
+        x = 0
+        for digit in str(number):
+           x = x * len(fromdigits) + fromdigits.index(digit)
+
+        # create the result in base 'len(todigits)'
+        if x == 0:
+            res = todigits[0]
+        else:
+            res = ""
+            while x > 0:
+                digit = x % len(todigits)
+                res = todigits[digit] + res
+                x = int(x / len(todigits))
+            if neg:
+                res = '-' + res
+        return res
+    convert = staticmethod(convert)
+
+bin = BaseConvertor('01')
+hexconv = BaseConvertor('0123456789ABCDEF')
+base62 = BaseConvertor(
+    'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz'
+)
+
+if __name__ == '__main__':
+    nums = [-10 ** 10, 10 ** 10] + range(-100, 100)
+    for convertor in [bin, hex, base62]:
+        for i in nums:
+            assert i == bin.to_decimal(bin.from_decimal(i)), '%s failed' % i
+