pylint: address several issues that were not previously reported.

Signed-off-by: Emmanuel Blot <[email protected]>

.pylintrc

@@ -12,6 +12,7 @@ disable=
     too-many-lines,
     too-many-locals,
     too-many-nested-blocks,
+    too-many-positional-arguments,
     too-many-public-methods,
     too-many-return-statements,
     too-many-statements,

pyftdi/ftdi.py

@@ -1781,8 +1781,9 @@ def write_data(self, data: Union[bytes, bytearray]) -> int:
             raise FtdiError(f'UsbError: {exc}') from exc
 
     def read_data_bytes(self, size: int, attempt: int = 1,
-                        request_gen: Optional[Callable[[int], bytes]] = None) \
-            -> bytes:
+            request_gen: Optional[Callable[[int],
+                                  Union[bytes, bytearray]]] = None) \
+        -> bytearray:
         """Read data from the FTDI interface
 
            In UART mode, data contains the serial stream read from the UART

pyftdi/i2c.py

@@ -653,7 +653,7 @@ def width(self) -> int:
         """
         return 16 if self._wide_port else 8
 
-    def read(self, address: int, readlen: int = 1,
+    def read(self, address: Optional[int], readlen: int = 1,
              relax: bool = True) -> bytes:
         """Read one or more bytes from a remote slave
 
@@ -695,7 +695,8 @@ def read(self, address: int, readlen: int = 1,
                     if do_epilog:
                         self._do_epilog()
 
-    def write(self, address: int, out: Union[bytes, bytearray, Iterable[int]],
+    def write(self, address: Optional[int],
+              out: Union[bytes, bytearray, Iterable[int]],
               relax: bool = True) -> None:
         """Write one or more bytes to a remote slave
 
@@ -713,10 +714,7 @@ def write(self, address: int, out: Union[bytes, bytearray, Iterable[int]],
         if not self.configured:
             raise I2cIOError("FTDI controller not initialized")
         self.validate_address(address)
-        if address is None:
-            i2caddress = None
-        else:
-            i2caddress = (address << 1) & self.HIGH
+        i2caddress = (address << 1) & self.HIGH if address is not None else None
         retries = self._retry_count
         do_epilog = True
         with self._lock:
@@ -735,9 +733,9 @@ def write(self, address: int, out: Union[bytes, bytearray, Iterable[int]],
                     if do_epilog:
                         self._do_epilog()
 
-    def exchange(self, address: int,
+    def exchange(self, address: Optional[int],
                  out: Union[bytes, bytearray, Iterable[int]],
-                 readlen: int = 0, relax: bool = True) -> bytes:
+                 readlen: int = 0, relax: bool = True) -> bytearray:
         """Send a byte sequence to a remote slave followed with
            a read request of one or more bytes.
 
@@ -767,12 +765,14 @@ def exchange(self, address: int,
             i2caddress = (address << 1) & self.HIGH
         retries = self._retry_count
         do_epilog = True
+        data = bytearray()
         with self._lock:
             while True:
                 try:
                     self._do_prolog(i2caddress)
                     self._do_write(out)
-                    self._do_prolog(i2caddress | self.BIT0)
+                    if i2caddress is not None:
+                        self._do_prolog(i2caddress | self.BIT0)
                     if readlen:
                         data = self._do_read(readlen)
                     do_epilog = relax
@@ -1017,7 +1017,7 @@ def _write_raw(self, data: int, write_high: bool):
             cmd = bytes([Ftdi.SET_BITS_LOW, low_data, low_dir])
         self._ftdi.write_data(cmd)
 
-    def _do_prolog(self, i2caddress: int) -> None:
+    def _do_prolog(self, i2caddress: Optional[int]) -> None:
         if i2caddress is None:
             return
         self.log.debug('   prolog 0x%x', i2caddress >> 1)
@@ -1061,7 +1061,7 @@ def _send_check_ack(self, cmd: bytearray):
         if ack[0] & self.BIT0:
             raise I2cNackError('NACK from slave')
 
-    def _do_read(self, readlen: int) -> bytes:
+    def _do_read(self, readlen: int) -> bytearray:
         self.log.debug('- read %d byte(s)', readlen)
         if not readlen:
             # force a real read request on device, but discard any result
@@ -1101,10 +1101,10 @@ def _do_read(self, readlen: int) -> bytes:
             cmd_chunk.extend(read_not_last * chunk_size)
             cmd_chunk.extend(self._immediate)
 
-            def write_command_gen(length: int):
+            def write_command_gen(length: int) -> bytearray:
                 if length <= 0:
                     # no more data
-                    return b''
+                    return bytearray()
                 if length <= chunk_size:
                     cmd = bytearray()
                     cmd.extend(read_not_last * (length-1))
@@ -1120,6 +1120,7 @@ def write_command_gen(length: int):
                 rem -= len(buf)
         else:
             while rem:
+                size = rem
                 if rem > chunk_size:
                     if not cmd:
                         # build the command sequence only once, as it may be
@@ -1132,7 +1133,6 @@ def write_command_gen(length: int):
                     cmd.extend(read_not_last * (rem-1))
                     cmd.extend(read_last)
                     cmd.extend(self._immediate)
-                    size = rem
                 self._ftdi.write_data(cmd)
                 buf = self._ftdi.read_data_bytes(size, 4)
                 self.log.debug('- read %d byte(s): %s',

pyftdi/usbtools.py

@@ -291,6 +291,7 @@ def parse_url(cls, urlstr: str, scheme: str,
             path = urlparts.path.strip('/')
             if path == '?' or (not path and urlstr.endswith('?')):
                 report_devices = True
+                interface = -1
             else:
                 interface = to_int(path)
                 report_devices = False