Add mypy typechecking

.travis.yml

@@ -12,12 +12,13 @@ install:
  - pushd tmp ; pip install -r ../requirements_dev.txt ; popd
  - pushd tmp ; pip install -r ../requirements.txt ; popd
  - if [[ $TRAVIS_PYTHON_VERSION == 2.7 ]]; then pip install enum34; fi
+ - if [[ $TRAVIS_PYTHON_VERSION == 3.6 ]]; then pip install mypy; fi
  - pushd tmp ; pip install codecov ; popd
  - python setup.py build_ext --inplace
 
 script:
+ - if [[ $TRAVIS_PYTHON_VERSION == 3.6 ]]; then make lint; fi
  - py.test --cov
- - make lint
 
 after_success:
  - bash <(curl -s https://codecov.io/bash)

Makefile

@@ -49,6 +49,7 @@ clean-test: ## remove test and coverage artifacts
 
 lint: ## check style with flake8
  flake8 pytoshop tests
+ mypy --py2 -p pytoshop
 
 test: ## run tests quickly with the default Python
  py.test

conda-environment-dev.yml

@@ -4,8 +4,9 @@ dependencies:
 - numpy >=1.11
 - pytest
 - pytest-cov
-- python >=3.5
+- python
 - sphinx >=1.4.0
 - coverage
 - flake8
 - six
+- typing

conda-environment.yml

@@ -2,5 +2,6 @@ name: pytoshop
 dependencies:
 - cython >=0.24
 - numpy >=1.11
-- python >=3.5
+- python
 - six
+- typing

mypy.ini

@@ -0,0 +1,5 @@
+[mypy]
+show_none_errors = True
+strict_optional = True
+ignore_missing_imports = True
+follow_imports = skip

pytoshop/__init__.py

@@ -12,7 +12,11 @@
 __version__ = '1.1.0'
 
 
+from typing import BinaryIO # NOQA
+
+
 def read(fd):
+ # type: (BinaryIO) -> PsdFile
  """
  Read a PSD file from a file-like object.
 

pytoshop/blending_range.py

@@ -16,13 +16,24 @@
 from . import util
 
 
+from typing import BinaryIO, List, Optional, TYPE_CHECKING # NOQA
+if TYPE_CHECKING:
+ from . import core # NOQA
+
+
 class BlendingRange(object):
  """
  Blending range data.
 
  Comprises 2 black values and 2 white values.
  """
- def __init__(self, black0=0, black1=0, white0=0, white1=0, _values=None):
+ def __init__(self,
+ black0=0, # type: int
+ black1=0, # type: int
+ white0=0, # type: int
+ white1=0, # type: int
+ _values=None # type: Optional[np.ndarray]
+ ): # type: (...) -> None
  if _values is not None:
  self._values = _values
  else:
@@ -31,40 +42,41 @@ def __init__(self, black0=0, black1=0, white0=0, white1=0, _values=None):
  np.uint8)
 
  @property
- def black0(self):
+ def black0(self): # type: (...) -> int
  return self._values[0]
 
  @black0.setter
- def black0(self, val):
+ def black0(self, val): # type: (int) -> None
  self._values[0] = val
 
  @property
- def black1(self):
+ def black1(self): # type: (...) -> int
  return self._values[1]
 
  @black1.setter
- def black1(self, val):
+ def black1(self, val): # type: (int) -> None
  self._values[1] = val
 
  @property
- def white0(self):
+ def white0(self): # type: (...) -> int
  return self._values[2]
 
  @white0.setter
- def white0(self, val):
+ def white0(self, val): # type: (int) -> None
  self._values[2] = val
 
  @property
- def white1(self):
+ def white1(self): # type: (...) -> int
  return self._values[3]
 
  @white1.setter
- def white1(self, val):
+ def white1(self, val): # type: (int) -> None
  self._values[3] = val
 
  @classmethod
  @util.trace_read
  def read(cls, fd):
+ # type: (BinaryIO) -> BlendingRange
  buf = fd.read(4)
  values = np.frombuffer(buf, np.uint8)
 
@@ -77,6 +89,7 @@ def read(cls, fd):
 
  @util.trace_write
  def write(self, fd, header):
+ # type: (BinaryIO, core.Header) -> None
  fd.write(self._values.tobytes())
  write.__doc__ = docs.write
 
@@ -87,7 +100,10 @@ class BlendingRangePair(object):
 
  The combination of a source and destination blending range.
  """
- def __init__(self, src=None, dst=None):
+ def __init__(self,
+ src=None, # type: Optional[BlendingRange]
+ dst=None # type: Optional[BlendingRange]
+ ): # type: (...) -> None
  if src is None:
  src = BlendingRange()
  if dst is None:
@@ -96,36 +112,37 @@ def __init__(self, src=None, dst=None):
  self._dst = dst
 
  @property
- def src(self):
+ def src(self): # type: (...) -> BlendingRange
  return self._src
 
  @src.setter
- def src(self, val):
+ def src(self, val): # type: (BlendingRange) -> None
  if not isinstance(val, BlendingRange):
  raise TypeError("src must be BlendingRange instance")
  self._src = val
 
  @property
- def dst(self):
+ def dst(self): # type: (...) -> BlendingRange
  return self._dst
 
  @dst.setter
- def dst(self, val):
+ def dst(self, val): # type: (BlendingRange) -> None
  if not isinstance(val, BlendingRange):
  raise TypeError("dst must be BlendingRange instance")
  self._dst = val
 
- def length(self, header):
+ def length(self, header): # type: (core.Header) -> int
  return 8
- length.__doc__ = docs.length
+ length.__doc__ = docs.length # type: ignore
 
- def total_length(self, header):
+ def total_length(self, header): # type: (core.Header) -> int
  return self.length(header)
- total_length.__doc__ = docs.total_length
+ total_length.__doc__ = docs.total_length # type: ignore
 
  @classmethod
  @util.trace_read
  def read(cls, fd):
+ # type: (BinaryIO) -> BlendingRangePair
  src = BlendingRange.read(fd)
  dst = BlendingRange.read(fd)
 
@@ -134,6 +151,7 @@ def read(cls, fd):
 
  @util.trace_write
  def write(self, fd, header):
+ # type: (BinaryIO, core.Header) -> None
  self.src.write(fd, header)
  self.dst.write(fd, header)
  write.__doc__ = docs.write
@@ -146,19 +164,24 @@ class BlendingRanges(object):
  Consists of a composite gray blend pair followed by N additional
  pairs.
  """
- def __init__(self, composite_gray_blend=None, channels=None):
+ def __init__(
+ self,
+ composite_gray_blend=None, # type: Optional[BlendingRangePair]
+ channels=None # type: Optional[List[BlendingRangePair]]
+ ): # type: (...) -> None
  self.composite_gray_blend = composite_gray_blend
  if channels is None:
  channels = []
  self.channels = channels
 
  @property
- def composite_gray_blend(self):
+ def composite_gray_blend(self): # type: (...) -> BlendingRangePair
  """Composite gray `BlendingRangePair`."""
  return self._composite_gray_blend
 
  @composite_gray_blend.setter
  def composite_gray_blend(self, value):
+ # type: (BlendingRangePair) -> None
  if (value is not None and
  not isinstance(value, BlendingRangePair)):
  raise TypeError(
@@ -168,16 +191,17 @@ def composite_gray_blend(self, value):
  self._composite_gray_blend = value
 
  @property
- def channels(self):
+ def channels(self): # type: (...) -> List[BlendingRangePair]
  """List of additional `BlendingRangePair` instances."""
  return self._channels
 
  @channels.setter
  def channels(self, value):
+ # type: (List[BlendingRangePair]) -> None
  util.assert_is_list_of(value, BlendingRangePair)
  self._channels = value
 
- def length(self, header):
+ def length(self, header): # type: (core.Header) -> int
  if (self.composite_gray_blend is not None or
  len(self.channels)):
  if self.composite_gray_blend is None:
@@ -188,15 +212,16 @@ def length(self, header):
  composite_gray_blend.total_length(header) +
  sum(x.total_length(header) for x in self.channels))
  return 0
- length.__doc__ = docs.length
+ length.__doc__ = docs.length # type: ignore
 
- def total_length(self, header):
+ def total_length(self, header): # type: (core.Header) -> int
  return 4 + self.length(header)
- total_length.__doc__ = docs.total_length
+ total_length.__doc__ = docs.total_length # type: ignore
 
  @classmethod
  @util.trace_read
  def read(cls, fd, num_channels):
+ # type: (BinaryIO, int) -> BlendingRanges
  length = util.read_value(fd, 'I')
  end = fd.tell() + length
  util.log("length: {}, end: {}", length, end)
@@ -217,6 +242,7 @@ def read(cls, fd, num_channels):
 
  @util.trace_write
  def write(self, fd, header):
+ # type: (BinaryIO, core.Header) -> None
  util.write_value(fd, 'I', self.length(header))
  if (self.composite_gray_blend is not None or
  len(self.channels)):