Fixed formatting

Author: coolsidd

conversions/base64_to_binary.py

@@ -92,8 +92,9 @@ def base64_to_bin(base64_str: str) -> str:
         b64_str = b64_str[1:]
     bin_str = ""
     for i, x in enumerate(b64_str):
-        if not x in B64_TO_BITS:
-            raise ValueError(f"Invalid base64 string. Invalid char {x} at pos {i}")
+        if x not in B64_TO_BITS:
+            exception_message = f"Invalid base64 string. Invalid char {x} at pos {i}"
+            raise ValueError(exception_message)
         bin_str += B64_TO_BITS[x]
     if is_negative:
         bin_str = "-" + bin_str