feat: function correctly encodes arabic number to chinese

src/codewars/kata_chinese_numeral_encoder.py

@@ -1,4 +1,4 @@
-C = {
+numerals = {
     "-": "负",
     ".": "点",
     0: "零",
@@ -15,50 +15,95 @@ C = {
     100: "百",
     1000: "千",
     10000: "万",
-    11: "十一",
-    12: "十二",
-    13: "十三",
-    14: "十四",
-    15: "十五",
-    16: "十六",
-    17: "十七",
-    18: "十八",
-    19: "十九",
 }
 
-D = {2: 10, 3: 100, 4: 1000, 5: 10000}
+# "Ten^x" dictonary
+T = {1: 0, 2: 10, 3: 100, 4: 1000, 5: 10000}
 
 
 def to_chinese_numeral(n):
-    # Check if n in C dictonary
-    try:
-        return C[n]
-    except KeyError:
-        pass
-
-    # Check if negative
+    # Check if negative, turn positive and remeber state
     if n < 0:
         n = abs(n)
         is_negative = True
     else:
         is_negative = False
 
-    """# Put single digits in list
-    split_number = [int(x) for x in str(n)]
-
-    arranged_number = []
-    for _ in range(0, len(split_number)):
-        arranged_number.append(split_number[0])
-        if len(split_number) in D:
-            arranged_number.append(D[len(split_number)])
-        split_number.pop(0)
-    if arranged_number[-1] == 0:
-        arranged_number.pop(-1)
-
+    # return C[n] if n in C dictonary
+    if n % 100 != 0:
+        try:
             if is_negative:
-        arranged_number.insert(0, "-")"""
+                return "".join([numerals["-"], numerals[n]])
+            else:
+                return numerals[n]
+        except KeyError:
+            pass
 
-    return is_negative
+    # Split number in iteger list and fractional (None if not exists)
+    if type(n) is not int:
+        n = str(n).split(".")
+        integer = [int(x) for x in n[0]]
+        fractional = [int(x) for x in n[1]]
+    else:
+        integer = [int(x) for x in str(n)]
+        fractional = None
 
+    # Blueprint list will contain building instruction on how to encode the number: 90090 -> [9, 10000, 0, 9, 10]
+    blueprint = []
 
-print(to_chinese_numeral(-90909))  # 9 10000 9
+    blueprint.append(integer[0])  # First digit won't be 0 it can just be appended
+    blueprint.append(T[len(integer)])  # Length of integer determines power of ten
+    integer.pop(0)  # Pop first digit
+
+    # create rest of blueprint by looping rest of integer
+    for _ in range(0, len(integer)):
+        # 0 needs no power of ten
+        if integer[0] == 0:
+            blueprint.append(0)
+        else:
+            blueprint.append(integer[0])
+            blueprint.append(T[len(integer)])
+        integer.pop(0)
+
+    # Pop last digit in blueprint if it's a 0
+    for i in range(len(blueprint) - 1, 0, -1):
+        if blueprint[i] == 0:
+            blueprint.pop(i)
+        else:
+            break
+
+    # Remove grouped zeros
+    was_zero = False
+    index_to_remove = []
+    for j, i in enumerate(blueprint):
+        if i == 0 and not was_zero:
+            was_zero = True
+        elif i == 0 and was_zero:
+            index_to_remove.append(j)
+        elif i != 0 and was_zero:
+            was_zero = False
+
+    index_to_remove.sort(
+        reverse=True
+    )  # Reverse indices to avoid index errors when applying pop()
+    [blueprint.pop(x) for x in index_to_remove]
+
+    # remove first item in blueprint if second item in blueprint is between 10 and 19. Skip step if index error
+    try:
+        if sum(blueprint[0:2]) == 11:
+            blueprint.pop(0)
+    except IndexError:
+        pass
+
+    # Add symbols - if n was negative and . if it was a fraction
+    if is_negative:
+        blueprint.insert(0, "-")
+
+    if fractional is not None:
+        blueprint.append(".")
+        [blueprint.append(x) for x in fractional]
+
+    # Apply chinese encoding to blueprint and fractional
+    encoding = [numerals[x] for x in blueprint]
+
+    return "".join(encoding)

tests/test_codewars/test_chinese_numeral_encoder.py

@@ -12,3 +12,4 @@ def test_to_chinese():
     assert to_chinese_numeral(10000) == "一万"
     assert to_chinese_numeral(10006) == "一万零六"
     assert to_chinese_numeral(10306.005) == "一万零三百零六点零零五"
+    assert to_chinese_numeral(-10.000001) == "负十点零零零零零一"