Added a working shorturl redirect view, with tests.

1 files changed, 65 insertions, 0 deletions

diff --git a/src/shorturls/baseconv.py b/src/shorturls/baseconv.py
new file mode 100644
index 0000000..9012441
--- /dev/null
+++ b/src/shorturls/baseconv.py
@@ -0,0 +1,65 @@
+"""
+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')
+>>> base20.from_decimal(1234)
+'31e'
+>>> base20.from_decimal('31e')
+1234
+"""
+
+class BaseConverter(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 = BaseConverter('01')
+hexconv = BaseConverter('0123456789ABCDEF')
+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
+