added decimal to hexadecimal conversion (#977)

* added decimal to hexadecimal conversion

* fixed error occuring as more digits were needed

conversions/decimal_to_hexadecimal.py

@@ -0,0 +1,43 @@
+""" Convert Base 10 (Decimal) Values to Hexadecimal Representations """
+
+# set decimal value for each hexadecimal digit
+values = {
+    0:'0',
+    1:'1',
+    2:'2',
+    3:'3',
+    4:'4',
+    5:'5',
+    6:'6',
+    7:'7',
+    8:'8',
+    9:'9',
+    10:'a',
+    11:'b',
+    12:'c',
+    13:'d',
+    14:'e',
+    15:'f'
+}
+
+def decimal_to_hexadecimal(decimal):
+    """ take decimal value, return hexadecimal representation as str """
+    hexadecimal = ''
+    while decimal > 0:
+        remainder = decimal % 16
+        decimal -= remainder
+        hexadecimal = values[remainder] + hexadecimal
+        decimal /= 16
+    return hexadecimal
+
+def main():
+    """ print test cases """
+    print("5 in hexadecimal is", decimal_to_hexadecimal(5))
+    print("15 in hexadecimal is", decimal_to_hexadecimal(15))
+    print("37 in hexadecimal is", decimal_to_hexadecimal(37))
+    print("255 in hexadecimal is", decimal_to_hexadecimal(255))
+    print("4096 in hexadecimal is", decimal_to_hexadecimal(4096))
+    print("999098 in hexadecimal is", decimal_to_hexadecimal(999098))
+
+if __name__ == '__main__':
+    main()