refactor: replace string concatenations with f-strings

youtube/proto_debug.py

@@ -179,7 +179,7 @@ def read_varint(data):
         except IndexError:
             if i == 0:
                 raise EOFError()
-            raise Exception('Unterminated varint starting at ' + str(data.tell() - i))
+            raise Exception(f'Unterminated varint starting at {data.tell() - i}')
         result |= (byte & 127) << 7*i
         if not byte & 128:
             break
@@ -235,8 +235,7 @@ def _make_protobuf(data):
             elif field[0] == 2:
                 result += string(field[1], _make_protobuf(field[2]))
             else:
-                raise NotImplementedError('Wire type ' + str(field[0])
-                    + ' not implemented')
+                raise NotImplementedError(f'Wire type {field[0]} not implemented')
         return result
     return data
 
@@ -286,7 +285,7 @@ def b64_to_bytes(data):
     if isinstance(data, bytes):
         data = data.decode('ascii')
     data = data.replace("%3D", "=")
-    return base64.urlsafe_b64decode(data + "="*((4 - len(data) % 4) % 4))
+    return base64.urlsafe_b64decode(f'{data}={"=" * ((4 - len(data) % 4) % 4)}')
 # --------------------------------------------------------------------
 
 
@@ -344,7 +343,7 @@ fromhex = bytes.fromhex
 
 
 def aligned_ascii(data):
-    return ' '.join(' ' + chr(n) if n in range(32, 128) else ' _' for n in data)
+    return ' '.join(f' {chr(n)}' if n in range(32, 128) else ' _' for n in data)
 
 
 def parse_protobuf(data, mutable=False, spec=()):
@@ -372,7 +371,7 @@ def parse_protobuf(data, mutable=False, spec=()):
         elif wire_type == 5:
             value = data.read(4)
         else:
-            raise Exception("Unknown wire type: " + str(wire_type) + ", Tag: " + bytes_to_hex(varint_encode(tag)) + ", at position " + str(data.tell()))
+            raise Exception(f"Unknown wire type: {wire_type}, Tag: {bytes_to_hex(varint_encode(tag))}, at position {data.tell()}")
         if mutable:
             yield [wire_type, field_number, value]
         else:
@@ -453,7 +452,7 @@ def b32decode(s, casefold=False, map01=None):
     if map01 is not None:
         map01 = _bytes_from_decode_data(map01)
         assert len(map01) == 1, repr(map01)
-        s = s.translate(bytes.maketrans(b'01', b'O' + map01))
+        s = s.translate(bytes.maketrans(b'01', f'O{map01.decode("ascii")}'))
     if casefold:
         s = s.upper()
     # Strip off pad characters from the right.  We need to count the pad
@@ -494,7 +493,7 @@ def b32decode(s, casefold=False, map01=None):
 def dec32(data):
     if isinstance(data, bytes):
         data = data.decode('ascii')
-    return b32decode(data + "="*((8 - len(data)%8)%8))
+    return b32decode(f'{data}={"=" * ((8 - len(data)%8)%8)}')
 
 
 _patterns = [
@@ -563,9 +562,7 @@ def _pp(obj, indent):   # not my best work
         if len(obj) == 3:   # (wire_type, field_number, data)
             return obj.__repr__()
         else:   # (base64, [...])
-            return ('(' + obj[0].__repr__() + ',\n'
-                    + indent_lines(_pp(obj[1], indent), indent) + '\n'
-                    + ')')
+            return f"({obj[0].__repr__()},\n{indent_lines(_pp(obj[1], indent), indent)}\n)"
     elif isinstance(obj, list):
         # [wire_type, field_number, data]
         if (len(obj) == 3
@@ -577,13 +574,11 @@ def _pp(obj, indent):   # not my best work
         elif (len(obj) == 3
             and not any(isinstance(x, (list, tuple)) for x in obj[0:2])
         ):
-            return ('[' + obj[0].__repr__() + ', ' + obj[1].__repr__() + ',\n'
-                    + indent_lines(_pp(obj[2], indent), indent) + '\n'
-                    + ']')
+            return f"[{obj[0].__repr__()}, {obj[1].__repr__()},\n{indent_lines(_pp(obj[2], indent), indent)}\n]"
         else:
             s = '[\n'
             for x in obj:
-                s += indent_lines(_pp(x, indent), indent) + ',\n'
+                s += f"{indent_lines(_pp(x, indent), indent)},\n"
             s += ']'
             return s
     else: