Merge pull request #43 from dhalbert/avoid-alloc

avoid allocations by avoiding **kwargs

Author: tannewt

adafruit_bus_device/i2c_device.py

@@ -61,12 +61,13 @@ class I2CDevice:
  def __init__(self, i2c, device_address, probe=True):
 
  self.i2c = i2c
+ self._has_write_read = hasattr(self.i2c, 'writeto_then_readfrom')
  self.device_address = device_address
 
  if probe:
  self.__probe_for_device()
 
- def readinto(self, buf, **kwargs):
+ def readinto(self, buf, *, start=0, end=None):
  """
  Read into ``buf`` from the device. The number of bytes read will be the
  length of ``buf``.
@@ -79,9 +80,9 @@ def readinto(self, buf, **kwargs):
  :param int start: Index to start writing at
  :param int end: Index to write up to but not include
  """
- self.i2c.readfrom_into(self.device_address, buf, **kwargs)
+ self.i2c.readfrom_into(self.device_address, buf, start=start, end=end)
 
- def write(self, buf, **kwargs):
+ def write(self, buf, *, start=0, end=None, stop=True):
  """
  Write the bytes from ``buffer`` to the device. Transmits a stop bit if
  ``stop`` is set.
@@ -95,7 +96,7 @@ def write(self, buf, **kwargs):
  :param int end: Index to read up to but not include
  :param bool stop: If true, output an I2C stop condition after the buffer is written
  """
- self.i2c.writeto(self.device_address, buf, **kwargs)
+ self.i2c.writeto(self.device_address, buf, start=start, end=end, stop=stop)
 
 #pylint: disable-msg=too-many-arguments
  def write_then_readinto(self, out_buffer, in_buffer, *,
@@ -129,7 +130,7 @@ def write_then_readinto(self, out_buffer, in_buffer, *,
  in_end = len(in_buffer)
  if stop:
  raise ValueError("Stop must be False. Use writeto instead.")
- if hasattr(self.i2c, 'writeto_then_readfrom'):
+ if self._has_write_read:
  # In linux, at least, this is a special kernel function call
  self.i2c.writeto_then_readfrom(self.device_address, out_buffer, in_buffer,
  out_start=out_start, out_end=out_end,
@@ -147,7 +148,7 @@ def __enter__(self):
  pass
  return self
 
- def __exit__(self, *exc):
+ def __exit__(self, exc_type, exc_val, exc_tb):
  self.i2c.unlock()
  return False
 

adafruit_bus_device/spi_device.py

@@ -85,7 +85,7 @@ def __enter__(self):
  self.chip_select.value = False
  return self.spi
 
- def __exit__(self, *exc):
+ def __exit__(self, exc_type, exc_val, exc_tb):
  if self.chip_select:
  self.chip_select.value = True
  if self.extra_clocks > 0: