verbose_reports: Add support for correct entropy for padded digits.

I have added the correct entropy information for when having padded
digits in the passphrase.

Fixes #5.

src/xkcd_pass/xkcd_pass.py

@@ -155,16 +155,30 @@ def verbose_reports(wordlist: List[str], options: argparse.Namespace) -> None:
     length = len(wordlist)
     numwords = options.numwords
 
-    bits = math.log(length, 2)
+    if options.no_padding_digits == False:
+        length = length + 9
+        numwords = numwords + options.padding_digits_num
+        bits = math.log(length, 2)
+        print("With the current options, your word list contains {0} words.".format(len(wordlist)))
 
-    print("With the current options, your word list contains {0} words.".format(length))
+        print(
+            "A {0} word password from this list with {1} appending digits will have roughly "
+            "{2} ({3:.3f} * {4}) bits of entropy,"
+            "".format(
+                options.numwords, options.padding_digits_num, int(bits * numwords), bits, numwords
+            )
+        )
+        print("assuming truly random word selection.\n")
+    else:
+        bits = math.log(length, 2)
+        print("With the current options, your word list contains {0} words.".format(length))
 
-    print(
-        "A {0} word password from this list will have roughly "
-        "{1} ({2:.2f} * {3}) bits of entropy,"
-        "".format(numwords, int(bits * numwords), bits, numwords)
-    )
-    print("assuming truly random word selection.\n")
+        print(
+            "A {0} word password from this list will have roughly "
+            "{1} ({2:.2f} * {3}) bits of entropy,"
+            "".format(numwords, int(bits * numwords), bits, numwords)
+        )
+        print("assuming truly random word selection.\n")
 
 
 def choose_words(wordlist: List[str], numwords: int) -> List[str]:

tests/test_xkcd_pass_main.py

@@ -51,7 +51,7 @@ def test_main_verbose(self) -> None:
             with self.stdout_patcher as mock_stdout:
                 xkcd_pass.main()
         output = mock_stdout.getvalue()
-        self.assertEqual(len(output.strip()), 199)
+        self.assertEqual(len(output.strip()), 225)
 
     def test_main_interactive(self) -> None:
         """

tests/test_xkcd_pass_verbose_reports.py

@@ -26,19 +26,37 @@ def setUp(self) -> None:
         self.options = argparse.Namespace(
             numwords=6,
             verbose=True,
+            no_padding_digits=False,
+            padding_digits_num=2,
         )
 
         self.stdout_patcher = mock.patch.object(sys, "stdout", new_callable=io.StringIO)
 
-    def test_verbose_output(self) -> None:
+    def test_verbose_output_with_padding_digits(self) -> None:
         """
-        Should display verbose reporting.
+        Should display verbose reporting with padding digits.
         """
         with self.stdout_patcher as mock_stdout:
             xkcd_pass.verbose_reports(wordlist=self.wordlist_small, options=self.options)
         output = mock_stdout.getvalue()
         expected_output = """
 With the current options, your word list contains 6 words.
+A 6 word password from this list with 2 appending digits will have roughly 31 (3.907 * 8) bits of entropy,
+assuming truly random word selection.
+""".strip()
+        self.assertEqual(output.strip(), expected_output)
+
+    def test_verbose_output_without_padding_digits(self) -> None:
+        """
+        Should display verbose reporting without padding digits.
+        """
+        self.options.no_padding_digits = True
+        self.options.padding_digits_num = None
+        with self.stdout_patcher as mock_stdout:
+            xkcd_pass.verbose_reports(wordlist=self.wordlist_small, options=self.options)
+        output = mock_stdout.getvalue()
+        expected_output = """
+With the current options, your word list contains 6 words.
 A 6 word password from this list will have roughly 15 (2.58 * 6) bits of entropy,
 assuming truly random word selection.
 """.strip()