Code cleanup

openflexure_microscope/camera/base.py

@@ -1,8 +1,5 @@
 # -*- coding: utf-8 -*-
-import datetime
 import logging
-import os
-import shutil
 import threading
 import time
 from abc import ABCMeta, abstractmethod
@@ -21,6 +18,7 @@ class BaseCamera(metaclass=ABCMeta):
 
         self.lock = StrictLock(name="Camera", timeout=None)
 
+        self.frames_iterator = None
         self.frame = None
         self.last_access = 0
         self.event = ClientEvent()
@@ -34,13 +32,11 @@ class BaseCamera(metaclass=ABCMeta):
     @abstractmethod
     def configuration(self):
         """The current camera configuration."""
-        pass
 
     @property
     @abstractmethod
     def state(self):
         """The current read-only camera state."""
-        pass
 
     @property
     def settings(self):
@@ -132,7 +128,6 @@ class BaseCamera(metaclass=ABCMeta):
     @abstractmethod
     def frames(self):
         """Create generator that returns frames from the camera."""
-        pass
 
     # WORKER THREAD
 

openflexure_microscope/camera/mock.py

@@ -1,8 +1,5 @@
 # -*- coding: utf-8 -*-
 
-"""
-"""
-
 from __future__ import division
 
 import io
@@ -11,18 +8,13 @@ import time
 from datetime import datetime
 
 # Type hinting
-from typing import Tuple
-
-import numpy as np
-from PIL import Image, ImageDraw, ImageFont
+from PIL import Image, ImageDraw
 
 from openflexure_microscope.camera.base import BaseCamera
-from openflexure_microscope.captures import CaptureObject
 
-"""
-PIL spams the logger with debug-level information. This is a pain when debugging api.app.
-We override the logging settings in api.app by setting a level for PIL here.
-"""
+# PIL spams the logger with debug-level information. This is a pain when debugging api.app.
+# We override the logging settings in api.app by setting a level for PIL here.
+
 pil_logger = logging.getLogger("PIL")
 pil_logger.setLevel(logging.INFO)
 
@@ -79,7 +71,6 @@ class MissingCamera(BaseCamera):
 
     def initialisation(self):
         """Run any initialisation code when the frame iterator starts."""
-        pass
 
     def close(self):
         """Close the Raspberry Pi PiCameraStreamer."""
@@ -134,7 +125,7 @@ class MissingCamera(BaseCamera):
                     "Cannot update camera config while recording is active."
                 )
 
-    def set_zoom(self, zoom_value: float = 1.0) -> None:
+    def set_zoom(self, *_) -> None:
         """
         Change the camera zoom, handling re-centering and scaling.
         """
@@ -142,7 +133,7 @@ class MissingCamera(BaseCamera):
 
     # LAUNCH ACTIONS
 
-    def start_preview(self, fullscreen=True, window=None):
+    def start_preview(self, *_):
         """Start the on board GPU camera preview."""
         logging.warning("GPU preview not implemented in mock camera")
 
@@ -150,7 +141,7 @@ class MissingCamera(BaseCamera):
         """Stop the on board GPU camera preview."""
         logging.warning("GPU preview not implemented in mock camera")
 
-    def start_recording(self, output, fmt: str = "h264", quality: int = 15):
+    def start_recording(self, *_):
         """Start recording.
 
         Start a new video recording, writing to a output object.
@@ -173,14 +164,7 @@ class MissingCamera(BaseCamera):
         with self.lock:
             logging.warning("Recording not implemented in mock camera")
 
-    def capture(
-        self,
-        output,
-        fmt: str = "jpeg",
-        use_video_port: bool = False,
-        resize: Tuple[int, int] = None,
-        bayer: bool = True,
-    ):
+    def capture(self, output, *_):
         """
         Capture a still image to a StreamObject.
 
@@ -189,10 +173,6 @@ class MissingCamera(BaseCamera):
 
         Args:
             output: String or file-like object to write capture data to
-            use_video_port (bool): Capture from the video port used for streaming. Lower resolution, faster.
-            fmt (str): Format of the capture.
-            resize ((int, int)): Resize the captured image.
-            bayer (bool): Store raw bayer data in capture
         """
 
         with self.lock:

openflexure_microscope/camera/pi.py

@@ -30,7 +30,6 @@ from __future__ import division
 
 import io
 import logging
-import os
 import time
 
 # Type hinting
@@ -43,13 +42,8 @@ import picamerax
 import picamerax.array
 
 from openflexure_microscope.camera.base import BaseCamera
-from openflexure_microscope.captures import CaptureObject
 from openflexure_microscope.paths import settings_file_path
-from openflexure_microscope.utilities import (
-    json_to_ndarray,
-    ndarray_to_json,
-    serialise_array_b64,
-)
+from openflexure_microscope.utilities import json_to_ndarray, ndarray_to_json
 
 # Richard's fix gain
 from .set_picamera_gain import set_analog_gain, set_digital_gain
@@ -117,6 +111,7 @@ class PiCameraStreamer(BaseCamera):
         )  #: str: Path of .npy lens shading table file
 
         # Start the stream worker on init
+        self.stream = None
         self.start_worker()
 
     @property
@@ -131,7 +126,6 @@ class PiCameraStreamer(BaseCamera):
 
     def initialisation(self):
         """Run any initialisation code when the frame iterator starts."""
-        pass
 
     def close(self):
         """Close the Raspberry Pi PiCameraStreamer."""
@@ -466,7 +460,7 @@ class PiCameraStreamer(BaseCamera):
 
             # Reduce the resolution for video streaming
             try:
-                self.camera._check_recording_stopped()
+                self.camera._check_recording_stopped()  # pylint: disable=W0212
             except picamerax.exc.PiCameraRuntimeError:
                 logging.info(
                     "Error while changing resolution: Recording already running."

openflexure_microscope/camera/piexif/_common.py

@@ -39,7 +39,7 @@ def read_exif_from_file(filename):
     head = data[2:6]
     HEAD_LENGTH = 4
     exif = None
-    while 1:
+    while len(head) == HEAD_LENGTH:
         length = struct.unpack(">H", head[2:4])[0]
 
         if head[:2] == b"\xff\xe1":

openflexure_microscope/camera/piexif/_dump.py

@@ -2,8 +2,8 @@ import copy
 import numbers
 import struct
 
-from ._common import *
-from ._exif import *
+from ._common import split_into_segments
+from ._exif import ExifIFD, ImageIFD, TAGS, TYPES
 
 TIFF_HEADER_LENGTH = 8
 
@@ -243,11 +243,11 @@ def _value_to_bytes(raw_value, value_type, offset):
     elif value_type == TYPES.Ascii:
         try:
             new_value = raw_value.encode("latin1") + b"\x00"
-        except:
+        except:  # pylint: disable=W0702
             try:
                 new_value = raw_value + b"\x00"
-            except TypeError:
-                raise ValueError("Got invalid type to convert.")
+            except TypeError as e:
+                raise ValueError("Got invalid type to convert.") from e
         length = len(new_value)
         if length > 4:
             value_str = struct.pack(">I", offset)
@@ -262,7 +262,7 @@ def _value_to_bytes(raw_value, value_type, offset):
         elif isinstance(raw_value[0], tuple):
             length = len(raw_value)
             new_value = b""
-            for n, val in enumerate(raw_value):
+            for _, val in enumerate(raw_value):
                 num, den = val
                 new_value += struct.pack(">L", num) + struct.pack(">L", den)
         value_str = struct.pack(">I", offset)
@@ -275,7 +275,7 @@ def _value_to_bytes(raw_value, value_type, offset):
         elif isinstance(raw_value[0], tuple):
             length = len(raw_value)
             new_value = b""
-            for n, val in enumerate(raw_value):
+            for _, val in enumerate(raw_value):
                 num, den = val
                 new_value += struct.pack(">l", num) + struct.pack(">l", den)
         value_str = struct.pack(">I", offset)
@@ -286,13 +286,13 @@ def _value_to_bytes(raw_value, value_type, offset):
             value_str = struct.pack(">I", offset)
             try:
                 four_bytes_over = b"" + raw_value
-            except TypeError:
-                raise ValueError("Got invalid type to convert.")
+            except TypeError as e:
+                raise ValueError("Got invalid type to convert.") from e
         else:
             try:
                 value_str = raw_value + b"\x00" * (4 - length)
-            except TypeError:
-                raise ValueError("Got invalid type to convert.")
+            except TypeError as e:
+                raise ValueError("Got invalid type to convert.") from e
     elif value_type == TYPES.SByte:  # Signed Byte
         length = len(raw_value)
         if length <= 4:
@@ -333,7 +333,7 @@ def _dict_to_bytes(ifd_dict, ifd, ifd_offset):
     entries = b""
     values = b""
 
-    for n, key in enumerate(sorted(ifd_dict)):
+    for _, key in enumerate(sorted(ifd_dict)):
         if (ifd == "0th") and (key in (ImageIFD.ExifTag, ImageIFD.GPSTag)):
             continue
         elif (ifd == "Exif") and (key == ExifIFD.InteroperabilityTag):
@@ -358,11 +358,11 @@ def _dict_to_bytes(ifd_dict, ifd, ifd_offset):
             length_str, value_str, four_bytes_over = _value_to_bytes(
                 raw_value, value_type, offset
             )
-        except ValueError:
+        except ValueError as e:
             raise ValueError(
                 '"dump" got wrong type of exif value.\n'
                 + "{0} in {1} IFD. Got as {2}.".format(key, ifd, type(ifd_dict[key]))
-            )
+            ) from e
 
         entries += key_str + type_str + length_str + value_str
         values += four_bytes_over

openflexure_microscope/camera/piexif/_insert.py

@@ -3,7 +3,7 @@ import struct
 import sys
 
 from . import _webp
-from ._common import *
+from ._common import merge_segments, split_into_segments
 from ._exceptions import InvalidImageDataError
 
 

openflexure_microscope/camera/piexif/_load.py

@@ -2,9 +2,9 @@ import struct
 import sys
 
 from . import _webp
-from ._common import *
+from ._common import get_exif_seg, read_exif_from_file, split_into_segments
 from ._exceptions import InvalidImageDataError
-from ._exif import *
+from ._exif import ExifIFD, ImageIFD, TAGS, TYPES
 
 LITTLE_ENDIAN = b"\x49\x49"
 
@@ -109,6 +109,8 @@ class _ExifReader(object):
                 else:
                     raise InvalidImageDataError("Given file is neither JPEG nor TIFF.")
 
+        self.endian_mark = None
+
     def get_ifd_dict(self, pointer, ifd_name, read_unknown=False):
         ifd_dict = {}
         tag_count = struct.unpack(

openflexure_microscope/camera/piexif/_remove.py

@@ -1,7 +1,7 @@
 import io
 
 from . import _webp
-from ._common import *
+from ._common import get_exif_seg, split_into_segments
 
 
 def remove(src, new_file=None):
@@ -42,7 +42,7 @@ def remove(src, new_file=None):
             new_data = src_data
         except Exception as e:
             print(e)
-            raise ValueError("Error occurred.")
+            raise ValueError("Error occurred.") from e
 
     if isinstance(new_file, io.BytesIO):
         new_file.write(new_data)

openflexure_microscope/camera/piexif/_transplant.py

@@ -1,6 +1,6 @@
 import io
 
-from ._common import *
+from ._common import get_exif_seg, merge_segments, split_into_segments
 
 
 def transplant(exif_src, image, new_file=None):

openflexure_microscope/camera/piexif/_webp.py

@@ -204,8 +204,6 @@ def get_exif(data):
     CHUNK_FOURCC_LENGTH = 4
     LENGTH_BYTES_LENGTH = 4
 
-    chunks = []
-    exif = b""
     while pointer < file_size:
         fourcc = data[pointer : pointer + CHUNK_FOURCC_LENGTH]
         pointer += CHUNK_FOURCC_LENGTH

openflexure_microscope/camera/piexif/helper.py

@@ -46,8 +46,8 @@ class UserComment:
                 cls._JIS_PREFIX: cls._JIS,
                 cls._UNICODE_PREFIX: cls._UNICODE,
             }[prefix]
-        except KeyError:
-            raise ValueError("unable to determine appropriate encoding")
+        except KeyError as e:
+            raise ValueError("unable to determine appropriate encoding") from e
         return body.decode(encoding, errors="replace")
 
     @classmethod

openflexure_microscope/camera/set_picamera_gain.py

@@ -4,7 +4,7 @@ import logging
 import time
 
 import picamerax
-from picamerax import exc, mmal, mmalobj
+from picamerax import exc, mmal
 from picamerax.mmalobj import to_rational
 
 MMAL_PARAMETER_ANALOG_GAIN = mmal.MMAL_PARAMETER_GROUP_CAMERA + 0x59
@@ -21,7 +21,7 @@ def set_gain(camera, gain, value):
     if gain not in [MMAL_PARAMETER_ANALOG_GAIN, MMAL_PARAMETER_DIGITAL_GAIN]:
         raise ValueError("The gain parameter was not valid")
     ret = mmal.mmal_port_parameter_set_rational(
-        camera._camera.control._port, gain, to_rational(value)
+        camera._camera.control._port, gain, to_rational(value)  # pylint: disable=W0212
     )
     if ret == 4:
         raise exc.PiCameraMMALError(