1 files changed, 36 insertions, 33 deletions

diff --git a/rsa/common.py b/rsa/common.py
index 39feb8c..bdbc90a 100644
--- a/rsa/common.py
+++ b/rsa/common.py
@@ -14,11 +14,11 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
-'''Common functionality shared by several modules.'''
+"""Common functionality shared by several modules."""
 
 
 def bit_size(num):
-    '''
+    """
     Number of bits needed to represent a integer excluding any prefix
     0 bits.
 
@@ -26,7 +26,7 @@ def bit_size(num):
     to match the behavior of the Python 3 API.
 
     Usage::
-    
+
         >>> bit_size(1023)
         10
         >>> bit_size(1024)
@@ -40,7 +40,7 @@ def bit_size(num):
         before the number's bit length is determined.
     :returns:
         Returns the number of bits in the integer.
-    '''
+    """
     if num == 0:
         return 0
     if num < 0:
@@ -51,23 +51,23 @@ def bit_size(num):
 
     hex_num = "%x" % num
     return ((len(hex_num) - 1) * 4) + {
-        '0':0, '1':1, '2':2, '3':2,
-        '4':3, '5':3, '6':3, '7':3,
-        '8':4, '9':4, 'a':4, 'b':4,
-        'c':4, 'd':4, 'e':4, 'f':4,
-     }[hex_num[0]]
+        '0': 0, '1': 1, '2': 2, '3': 2,
+        '4': 3, '5': 3, '6': 3, '7': 3,
+        '8': 4, '9': 4, 'a': 4, 'b': 4,
+        'c': 4, 'd': 4, 'e': 4, 'f': 4,
+    }[hex_num[0]]
 
 
 def _bit_size(number):
-    '''
+    """
     Returns the number of bits required to hold a specific long number.
-    '''
+    """
     if number < 0:
         raise ValueError('Only nonnegative numbers possible: %s' % number)
 
     if number == 0:
         return 0
-    
+
     # This works, even with very large numbers. When using math.log(number, 2),
     # you'll get rounding errors and it'll fail.
     bits = 0
@@ -79,9 +79,9 @@ def _bit_size(number):
 
 
 def byte_size(number):
-    '''
+    """
     Returns the number of bytes required to hold a specific long number.
-    
+
     The number of bytes is rounded up.
 
     Usage::
@@ -97,17 +97,17 @@ def byte_size(number):
         An unsigned integer
     :returns:
         The number of bytes required to hold a specific long number.
-    '''
+    """
     quanta, mod = divmod(bit_size(number), 8)
     if mod or number == 0:
         quanta += 1
     return quanta
-    #return int(math.ceil(bit_size(number) / 8.0))
+    # return int(math.ceil(bit_size(number) / 8.0))
 
 
 def extended_gcd(a, b):
-    '''Returns a tuple (r, i, j) such that r = gcd(a, b) = ia + jb
-    '''
+    """Returns a tuple (r, i, j) such that r = gcd(a, b) = ia + jb
+    """
     # r = gcd(a,b) i = multiplicitive inverse of a mod b
     #      or      j = multiplicitive inverse of b mod a
     # Neg return values for i or j are made positive mod b or a respectively
@@ -116,26 +116,28 @@ def extended_gcd(a, b):
     y = 1
     lx = 1
     ly = 0
-    oa = a                             #Remember original a/b to remove 
-    ob = b                             #negative values from return results
+    oa = a  # Remember original a/b to remove
+    ob = b  # negative values from return results
     while b != 0:
         q = a // b
-        (a, b)  = (b, a % b)
-        (x, lx) = ((lx - (q * x)),x)
-        (y, ly) = ((ly - (q * y)),y)
-    if (lx < 0): lx += ob              #If neg wrap modulo orignal b
-    if (ly < 0): ly += oa              #If neg wrap modulo orignal a
-    return (a, lx, ly)                 #Return only positive values
+        (a, b) = (b, a % b)
+        (x, lx) = ((lx - (q * x)), x)
+        (y, ly) = ((ly - (q * y)), y)
+    if lx < 0:
+        lx += ob  # If neg wrap modulo orignal b
+    if ly < 0:
+        ly += oa  # If neg wrap modulo orignal a
+    return a, lx, ly  # Return only positive values
 
 
 def inverse(x, n):
-    '''Returns x^-1 (mod n)
+    """Returns x^-1 (mod n)
 
     >>> inverse(7, 4)
     3
     >>> (inverse(143, 4) * 143) % 4
     1
-    '''
+    """
 
     (divider, inv, _) = extended_gcd(x, n)
 
@@ -146,14 +148,14 @@ def inverse(x, n):
 
 
 def crt(a_values, modulo_values):
-    '''Chinese Remainder Theorem.
+    """Chinese Remainder Theorem.
 
     Calculates x such that x = a[i] (mod m[i]) for each i.
 
     :param a_values: the a-values of the above equation
     :param modulo_values: the m-values of the above equation
     :returns: x such that x = a[i] (mod m[i]) for each i
-    
+
 
     >>> crt([2, 3], [3, 5])
     8
@@ -163,10 +165,10 @@ def crt(a_values, modulo_values):
 
     >>> crt([2, 3, 0], [7, 11, 15])
     135
-    '''
+    """
 
     m = 1
-    x = 0 
+    x = 0
 
     for modulo in modulo_values:
         m *= modulo
@@ -179,7 +181,8 @@ def crt(a_values, modulo_values):
 
     return x
 
+
 if __name__ == '__main__':
     import doctest
-    doctest.testmod()
 
+    doctest.testmod()