ashumkin · June 27, 2019 13:55 · Jun 27, 2019
diff --git a/inn-calc.py b/inn-calc.py
@@ -0,0 +1,41 @@
+import sys
+
+if len(sys.argv) > 1:
+    supposed_inn = sys.argv[1]
+else:
+    supposed_inn = "123456789"
+
+def calc_checksum_digit(weights, inn):
+    inn_splitted = list(map(int, inn))
+    res = 0
+    for i in range(len(inn_splitted)):
+        res += inn_splitted[i] * weights[i]
+    res %= 11
+    if res > 9:
+        res %= 10
+    return str(res)
+
+def calc_checksum_digit_individuals(inn):
+    inn = inn[:10]
+    c1 = calc_checksum_digit((7,2,4,10,3,5,9,4,6,8,0), inn)
+    c2 = calc_checksum_digit((3,7,2,4,10,3,5,9,4,6,8,0), inn + c1)
+    return inn + c1 + c2
+
+def calc_checksum_digit_jl(inn):
+    inn = inn[:9]
+    c = calc_checksum_digit((2,4,10,3,5,9,4,6,8,0), inn)
+    return inn + c
+
+def calc_checksum_digit_for_inn(inn):
+    if len(inn) >= 10:
+        return calc_checksum_digit_individuals(inn)
+    elif len(inn) >= 9:
+        return calc_checksum_digit_jl(inn)
+    else:
+        return None
+
+inn = calc_checksum_digit_for_inn(supposed_inn)
+if inn is None:
+    print("Invalid INN", supposed_inn)
+else:
+    print(inn)