README typo

.gitignore

@@ -1,2 +1,3 @@
 galois-git/
 galois
+__pycache__

README.md

@@ -11,7 +11,7 @@ This code can correct up to 8 bit errors.
 
 ## AVR 
 
-Here you find space efficient code for an AVR µC, in C and assmebler.
+Here you find space efficient code for an AVR µC, in C and assembler.
 
 ## Python
 

bch4369.py

@@ -51,8 +51,11 @@ class bch4369():
     def load_galois(self):
         if self.galois is not None:
             return
+        print("BCH4369: loading module galois …", file=stderr)
         from galois import BCH, GF
+        print("BCH4369: … building BCH(4369) …", file=stderr)
         self.galois = BCH(4369, 4369-128, extension_field=GF(2**16))
+        print("BCH4369: … done.", file=stderr)
 
     def decode(self, *a, **aa):
         self.load_galois()
@@ -78,13 +81,19 @@ class bch4369():
             return True
         return False
 
+    class BCHError(IOError):
+        pass
+
     def fix_page(self, b, what='codeword'):
         a, e = self.decode(self.bytes2bits(self.salt + b), output=what, errors=True)
         m = self.bits2bytes(a)
-        if e:
+        if not e:
-            print(f"BCH4369: {e} errors corrected", file=stderr)
+            return b
-            if m[:len(self.salt)] != self.salt:
+        if e<0:
-                print(f"BCH4369: error in the salt {self.salt!r} → {m[:len(self.salt)]!r}", file=stderr)
+            raise self.BCHError(f"BCH4369: {e=}: cannot correct errors")
+        print(f"BCH4369: {e} errors corrected", file=stderr)
+        if m[:len(self.salt)] != self.salt:
+            print(f"BCH4369: error in the salt {self.salt!r} → {m[:len(self.salt)]!r}", file=stderr)
         return m[len(self.salt):]
 
     bitv = (0x80 >> arange(8, dtype=uint8)).reshape((1,8))