Data commit

Task/Validate-International-Securities-Identification-Number/Python/validate-international-securities-identification-number.py

@@ -0,0 +1,33 @@
+def check_isin(a):
+    if len(a) != 12 or not all(c.isalpha() for c in a[:2]) or not all(c.isalnum() for c in a[2:]):
+        return False
+    s = "".join(str(int(c, 36)) for c in a)
+    return 0 == (sum(sum(divmod(2 * (ord(c) - 48), 10)) for c in s[-2::-2]) +
+                 sum(ord(c) - 48 for c in s[::-2])) % 10
+
+# A more readable version
+def check_isin_alt(a):
+    if len(a) != 12:
+        return False
+    s = []
+    for i, c in enumerate(a):
+        if c.isdigit():
+            if i < 2:
+                return False
+            s.append(ord(c) - 48)
+        elif c.isupper():
+            if i == 11:
+                return False
+            s += divmod(ord(c) - 55, 10)
+        else:
+            return False
+    v = sum(s[::-2])
+    for k in s[-2::-2]:
+        k = 2 * k
+        v += k - 9 if k > 9 else k
+    return v % 10 == 0
+
+[check_isin(s) for s in ["US0378331005", "US0373831005", "U50378331005", "US03378331005",
+                         "AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040"]]
+
+# [True, False, False, False, True, True, True]