dice.py: Factored string-based dice creation into a @classmethod

dice.py

@@ -13,6 +13,43 @@ import argparse
 
 # Implements a "dice" - that is, a series of dice plus modifiers
 class Dice():
+    # This builds dice out of a simple input format
+    # All of the dark regex magic is contained to this function,
+    # lest it corrupt innocent code
+    @classmethod
+    def from_desc(cls, desc):
+        if not re.match(r'^\d+d\d+', desc):
+            raise Exception('Dice format invalid. See --help')
+
+        (n, s) = re.match(r'^(\d+)d(\d+)', desc).groups()
+        num = int(n)
+        sides = int(s)
+        mod = 0
+        drop_low = 0
+        drop_high = 0
+        reroll = 0
+        reroll_times = 0
+
+        for m in re.findall(r'[dD+-]\d+', desc):
+            if m[0] == '-':
+                mod += int(m)
+            elif m[0] == '+':
+                mod += int(m[1:])
+            elif m[0] == 'D':
+                drop_high = int(m[1:])
+            elif m[0] == 'd':
+                drop_low = int(m[1:])
+
+        m = re.search(r'r(\d+)(x\d+)?', desc)
+        if m:
+            (r, rt) = m.groups()
+            reroll = int(r)
+            if rt:
+                reroll_times = int(rt[1:])
+
+        return cls(num, sides, mod, drop_low, drop_high, reroll, reroll_times)
+
+
     def __init__(self, num, sides, mod, drop_low=0, drop_high=0, reroll=0, reroll_times=0):
         self.num = num
         self.sides = sides
@@ -23,7 +60,13 @@ class Dice():
         self.reroll_times = reroll_times
         self.times_rolled = 0
 
-    # Rolls the dice, prints the result
+
+    def num_rolls(self):
+        return self.times_rolled
+
+        
+    # Rolls the dice, returns a structure
+    # containing the result plus metadata
     def roll(self, verbose=False):
         results = []
         rerolled = []
@@ -103,43 +146,12 @@ class Dice():
         return "{num}d{sides}{mod}{drop}{reroll}".format(num=self.num, sides=self.sides, mod=mod_info, drop=drop_info, reroll=reroll_info)
         
         
-
-# This builds dice out of a simple input format
-# All of the dark regex magic is contained to this function,
-# lest it corrupt innocent code
+# This takes command-line input as dice description strings
+# and builds a list of Dice objects
 def parse_input(args):
     dice_list = []
     for arg in args:
-        if not re.match(r'^\d+d\d+', arg):
-            continue
-
-        (n, s) = re.match(r'^(\d+)d(\d+)', arg).groups()
-        num = int(n)
-        sides = int(s)
-        mod = 0
-        dlow = 0
-        dhigh = 0
-        reroll = 0
-        reroll_times = 0
-
-        for m in re.findall(r'[dD+-]\d+', arg):
-            if m[0] == '-':
-                mod += int(m)
-            elif m[0] == '+':
-                mod += int(m[1:])
-            elif m[0] == 'D':
-                dhigh = int(m[1:])
-            elif m[0] == 'd':
-                dlow = int(m[1:])
-
-        m = re.search(r'r(\d+)(x\d+)?', arg)
-        if m:
-            (r, rt) = m.groups()
-            reroll = int(r)
-            if rt:
-                reroll_times = int(rt[1:])
-
-        dice_list.append(Dice(num, sides, mod, drop_low=dlow, drop_high=dhigh, reroll=reroll, reroll_times=reroll_times))
+        dice_list.append(Dice.from_desc(arg))
 
     return dice_list