Turn on lint checking and consolidate python requirements.

Having the dependencies in .travis.yml makes it clearer that it
has no runtime dependencies.

.pylintrc

@@ -0,0 +1,425 @@
+[MASTER]
+
+# A comma-separated list of package or module names from where C extensions may
+# be loaded. Extensions are loading into the active Python interpreter and may
+# run arbitrary code
+extension-pkg-whitelist=
+
+# Add files or directories to the blacklist. They should be base names, not
+# paths.
+ignore=CVS
+
+# Add files or directories matching the regex patterns to the blacklist. The
+# regex matches against base names, not paths.
+ignore-patterns=
+
+# Python code to execute, usually for sys.path manipulation such as
+# pygtk.require().
+#init-hook=
+
+# Use multiple processes to speed up Pylint.
+jobs=2
+
+# List of plugins (as comma separated values of python modules names) to load,
+# usually to register additional checkers.
+load-plugins=
+
+# Pickle collected data for later comparisons.
+persistent=yes
+
+# Specify a configuration file.
+#rcfile=
+
+# Allow loading of arbitrary C extensions. Extensions are imported into the
+# active Python interpreter and may run arbitrary code.
+unsafe-load-any-extension=no
+
+
+[MESSAGES CONTROL]
+
+# Only show warnings with the listed confidence levels. Leave empty to show
+# all. Valid levels: HIGH, INFERENCE, INFERENCE_FAILURE, UNDEFINED
+confidence=
+
+# Disable the message, report, category or checker with the given id(s). You
+# can either give multiple identifiers separated by comma (,) or put this
+# option multiple times (only on the command line, not in the configuration
+# file where it should appear only once).You can also use "--disable=all" to
+# disable everything first and then reenable specific checks. For example, if
+# you want to run only the similarities checker, you can use "--disable=all
+# --enable=similarities". If you want to run only the classes checker, but have
+# no Warning level messages displayed, use"--disable=all --enable=classes
+# --disable=W"
+disable=print-statement,parameter-unpacking,unpacking-in-except,old-raise-syntax,backtick,long-suffix,old-ne-operator,old-octal-literal,import-star-module-level,raw-checker-failed,bad-inline-option,locally-disabled,locally-enabled,file-ignored,suppressed-message,useless-suppression,deprecated-pragma,apply-builtin,basestring-builtin,buffer-builtin,cmp-builtin,coerce-builtin,execfile-builtin,file-builtin,long-builtin,raw_input-builtin,reduce-builtin,standarderror-builtin,unicode-builtin,xrange-builtin,coerce-method,delslice-method,getslice-method,setslice-method,no-absolute-import,old-division,dict-iter-method,dict-view-method,next-method-called,metaclass-assignment,indexing-exception,raising-string,reload-builtin,oct-method,hex-method,nonzero-method,cmp-method,input-builtin,round-builtin,intern-builtin,unichr-builtin,map-builtin-not-iterating,zip-builtin-not-iterating,range-builtin-not-iterating,filter-builtin-not-iterating,using-cmp-argument,eq-without-hash,div-method,idiv-method,rdiv-method,exception-message-attribute,invalid-str-codec,sys-max-int,bad-python3-import,deprecated-string-function,deprecated-str-translate-call,import-error
+
+# Enable the message, report, category or checker with the given id(s). You can
+# either give multiple identifier separated by comma (,) or put this option
+# multiple time (only on the command line, not in the configuration file where
+# it should appear only once). See also the "--disable" option for examples.
+enable=
+
+
+[REPORTS]
+
+# Python expression which should return a note less than 10 (10 is the highest
+# note). You have access to the variables errors warning, statement which
+# respectively contain the number of errors / warnings messages and the total
+# number of statements analyzed. This is used by the global evaluation report
+# (RP0004).
+evaluation=10.0 - ((float(5 * error + warning + refactor + convention) / statement) * 10)
+
+# Template used to display messages. This is a python new-style format string
+# used to format the message information. See doc for all details
+#msg-template=
+
+# Set the output format. Available formats are text, parseable, colorized, json
+# and msvs (visual studio).You can also give a reporter class, eg
+# mypackage.mymodule.MyReporterClass.
+output-format=text
+
+# Tells whether to display a full report or only the messages
+reports=no
+
+# Activate the evaluation score.
+score=yes
+
+
+[REFACTORING]
+
+# Maximum number of nested blocks for function / method body
+max-nested-blocks=5
+
+
+[LOGGING]
+
+# Logging modules to check that the string format arguments are in logging
+# function parameter format
+logging-modules=logging
+
+
+[SPELLING]
+
+# Spelling dictionary name. Available dictionaries: none. To make it working
+# install python-enchant package.
+spelling-dict=
+
+# List of comma separated words that should not be checked.
+spelling-ignore-words=
+
+# A path to a file that contains private dictionary; one word per line.
+spelling-private-dict-file=
+
+# Tells whether to store unknown words to indicated private dictionary in
+# --spelling-private-dict-file option instead of raising a message.
+spelling-store-unknown-words=no
+
+
+[MISCELLANEOUS]
+
+# List of note tags to take in consideration, separated by a comma.
+notes=FIXME,XXX,TODO
+
+
+[TYPECHECK]
+
+# List of decorators that produce context managers, such as
+# contextlib.contextmanager. Add to this list to register other decorators that
+# produce valid context managers.
+contextmanager-decorators=contextlib.contextmanager
+
+# List of members which are set dynamically and missed by pylint inference
+# system, and so shouldn't trigger E1101 when accessed. Python regular
+# expressions are accepted.
+generated-members=
+
+# Tells whether missing members accessed in mixin class should be ignored. A
+# mixin class is detected if its name ends with "mixin" (case insensitive).
+ignore-mixin-members=yes
+
+# This flag controls whether pylint should warn about no-member and similar
+# checks whenever an opaque object is returned when inferring. The inference
+# can return multiple potential results while evaluating a Python object, but
+# some branches might not be evaluated, which results in partial inference. In
+# that case, it might be useful to still emit no-member and other checks for
+# the rest of the inferred objects.
+ignore-on-opaque-inference=yes
+
+# List of class names for which member attributes should not be checked (useful
+# for classes with dynamically set attributes). This supports the use of
+# qualified names.
+ignored-classes=optparse.Values,thread._local,_thread._local
+
+# List of module names for which member attributes should not be checked
+# (useful for modules/projects where namespaces are manipulated during runtime
+# and thus existing member attributes cannot be deduced by static analysis. It
+# supports qualified module names, as well as Unix pattern matching.
+ignored-modules=
+
+# Show a hint with possible names when a member name was not found. The aspect
+# of finding the hint is based on edit distance.
+missing-member-hint=yes
+
+# The minimum edit distance a name should have in order to be considered a
+# similar match for a missing member name.
+missing-member-hint-distance=1
+
+# The total number of similar names that should be taken in consideration when
+# showing a hint for a missing member.
+missing-member-max-choices=1
+
+
+[VARIABLES]
+
+# List of additional names supposed to be defined in builtins. Remember that
+# you should avoid to define new builtins when possible.
+additional-builtins=
+
+# Tells whether unused global variables should be treated as a violation.
+allow-global-unused-variables=yes
+
+# List of strings which can identify a callback function by name. A callback
+# name must start or end with one of those strings.
+callbacks=cb_,_cb
+
+# A regular expression matching the name of dummy variables (i.e. expectedly
+# not used).
+dummy-variables-rgx=_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy|^ignored_|^unused_
+
+# Argument names that match this expression will be ignored. Default to name
+# with leading underscore
+ignored-argument-names=_.*|^ignored_|^unused_
+
+# Tells whether we should check for unused import in __init__ files.
+init-import=no
+
+# List of qualified module names which can have objects that can redefine
+# builtins.
+redefining-builtins-modules=six.moves,future.builtins
+
+
+[FORMAT]
+
+# Expected format of line ending, e.g. empty (any line ending), LF or CRLF.
+expected-line-ending-format=LF
+
+# Regexp for a line that is allowed to be longer than the limit.
+ignore-long-lines=^\s*(# )?<?https?://\S+>?$
+
+# Number of spaces of indent required inside a hanging  or continued line.
+indent-after-paren=4
+
+# String used as indentation unit. This is usually "    " (4 spaces) or "\t" (1
+# tab).
+indent-string='    '
+
+# Maximum number of characters on a single line.
+max-line-length=100
+
+# Maximum number of lines in a module
+max-module-lines=1000
+
+# List of optional constructs for which whitespace checking is disabled. `dict-
+# separator` is used to allow tabulation in dicts, etc.: {1  : 1,\n222: 2}.
+# `trailing-comma` allows a space between comma and closing bracket: (a, ).
+# `empty-line` allows space-only lines.
+no-space-check=trailing-comma,dict-separator
+
+# Allow the body of a class to be on the same line as the declaration if body
+# contains single statement.
+single-line-class-stmt=no
+
+# Allow the body of an if to be on the same line as the test if there is no
+# else.
+single-line-if-stmt=no
+
+
+[SIMILARITIES]
+
+# Ignore comments when computing similarities.
+ignore-comments=yes
+
+# Ignore docstrings when computing similarities.
+ignore-docstrings=yes
+
+# Ignore imports when computing similarities.
+ignore-imports=no
+
+# Minimum lines number of a similarity.
+min-similarity-lines=4
+
+
+[BASIC]
+
+# Naming hint for argument names
+argument-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Regular expression matching correct argument names
+argument-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Naming hint for attribute names
+attr-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Regular expression matching correct attribute names
+attr-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Bad variable names which should always be refused, separated by a comma
+bad-names=foo,bar,baz,toto,tutu,tata
+
+# Naming hint for class attribute names
+class-attribute-name-hint=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
+
+# Regular expression matching correct class attribute names
+class-attribute-rgx=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
+
+# Naming hint for class names
+class-name-hint=[A-Z_][a-zA-Z0-9_]+$
+
+# Regular expression matching correct class names
+class-rgx=[A-Z_][a-zA-Z0-9_]+$
+
+# Naming hint for constant names
+const-name-hint=(([A-Z_][A-Z0-9_]*)|(__.*__))$
+
+# Regular expression matching correct constant names
+const-rgx=(([A-Z_][A-Z0-9_]*)|(__.*__))$
+
+# Minimum line length for functions/classes that require docstrings, shorter
+# ones are exempt.
+docstring-min-length=-1
+
+# Naming hint for function names
+function-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Regular expression matching correct function names
+function-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Good variable names which should always be accepted, separated by a comma
+good-names=r,g,b,i,j,k,n,ex,Run,_
+
+# Include a hint for the correct naming format with invalid-name
+include-naming-hint=no
+
+# Naming hint for inline iteration names
+inlinevar-name-hint=[A-Za-z_][A-Za-z0-9_]*$
+
+# Regular expression matching correct inline iteration names
+inlinevar-rgx=[A-Za-z_][A-Za-z0-9_]*$
+
+# Naming hint for method names
+method-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Regular expression matching correct method names
+method-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Naming hint for module names
+module-name-hint=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
+
+# Regular expression matching correct module names
+module-rgx=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
+
+# Colon-delimited sets of names that determine each other's naming style when
+# the name regexes allow several styles.
+name-group=
+
+# Regular expression which should only match function or class names that do
+# not require a docstring.
+no-docstring-rgx=^_
+
+# List of decorators that produce properties, such as abc.abstractproperty. Add
+# to this list to register other decorators that produce valid properties.
+property-classes=abc.abstractproperty
+
+# Naming hint for variable names
+variable-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+# Regular expression matching correct variable names
+variable-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
+
+
+[IMPORTS]
+
+# Allow wildcard imports from modules that define __all__.
+allow-wildcard-with-all=no
+
+# Analyse import fallback blocks. This can be used to support both Python 2 and
+# 3 compatible code, which means that the block might have code that exists
+# only in one or another interpreter, leading to false positives when analysed.
+analyse-fallback-blocks=no
+
+# Deprecated modules which should not be used, separated by a comma
+deprecated-modules=optparse,tkinter.tix
+
+# Create a graph of external dependencies in the given file (report RP0402 must
+# not be disabled)
+ext-import-graph=
+
+# Create a graph of every (i.e. internal and external) dependencies in the
+# given file (report RP0402 must not be disabled)
+import-graph=
+
+# Create a graph of internal dependencies in the given file (report RP0402 must
+# not be disabled)
+int-import-graph=
+
+# Force import order to recognize a module as part of the standard
+# compatibility libraries.
+known-standard-library=
+
+# Force import order to recognize a module as part of a third party library.
+known-third-party=enchant
+
+
+[CLASSES]
+
+# List of method names used to declare (i.e. assign) instance attributes.
+defining-attr-methods=__init__,__new__,setUp
+
+# List of member names, which should be excluded from the protected access
+# warning.
+exclude-protected=_asdict,_fields,_replace,_source,_make
+
+# List of valid names for the first argument in a class method.
+valid-classmethod-first-arg=cls
+
+# List of valid names for the first argument in a metaclass class method.
+valid-metaclass-classmethod-first-arg=mcs
+
+
+[DESIGN]
+
+# Maximum number of arguments for function / method
+max-args=5
+
+# Maximum number of attributes for a class (see R0902).
+max-attributes=11
+
+# Maximum number of boolean expressions in a if statement
+max-bool-expr=5
+
+# Maximum number of branch for function / method body
+max-branches=12
+
+# Maximum number of locals for function / method body
+max-locals=15
+
+# Maximum number of parents for a class (see R0901).
+max-parents=7
+
+# Maximum number of public methods for a class (see R0904).
+max-public-methods=20
+
+# Maximum number of return / yield for function / method body
+max-returns=6
+
+# Maximum number of statements in function / method body
+max-statements=50
+
+# Minimum number of public methods for a class (see R0903).
+min-public-methods=2
+
+
+[EXCEPTIONS]
+
+# Exceptions that will emit a warning when being caught. Defaults to
+# "Exception"
+overgeneral-exceptions=Exception

.travis.yml

@@ -21,4 +21,10 @@ deploy:
   on:
     tags: true
 
-script: circuitpython-build-bundles --filename_prefix adafruit-circuitpython-dotstar --library_location .
+install:
+  - pip install pylint circuitpython-travis-build-tools
+
+script:
+  - pylint adafruit_dotstar.py
+  - ([[ ! -d "examples" ]] || pylint --disable=missing-docstring,invalid-name examples/*.py)
+  - circuitpython-build-bundles --filename_prefix adafruit-circuitpython-dotstar --library_location .

README.rst

@@ -6,10 +6,6 @@ Adafruit CircuitPython DotStar
     :target: https://circuitpython.readthedocs.io/projects/dotstar/en/latest/
     :alt: Documentation Status
 
-.. image :: https://badges.gitter.im/adafruit/circuitpython.svg
-    :target: https://gitter.im/adafruit/circuitpython?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge
-    :alt: Gitter
-
 .. image :: https://img.shields.io/discord/327254708534116352.svg
     :target: https://adafru.it/discord
     :alt: Discord

adafruit_dotstar.py

@@ -28,10 +28,13 @@
 
 * Author(s): Damien P. George, Limor Fried & Scott Shawcroft
 """
+import math
+
 import busio
 import digitalio
-import math
-import time
+
+__version__ = "0.0.0-auto.0"
+__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_DotStar.git"
 
 class DotStar:
     """
@@ -41,7 +44,8 @@ class DotStar:
     :param ~microcontroller.Pin data: The pin to output dotstar data on.
     :param int n: The number of dotstars in the chain
     :param float brightness: Brightness of the pixels between 0.0 and 1.0
-    :param bool auto_write: True if the dotstars should immediately change when set. If False, `show` must be called explicitly.
+    :param bool auto_write: True if the dotstars should immediately change when
+        set. If False, `show` must be called explicitly.
 
 
     Example for Gemma M0:
@@ -59,37 +63,38 @@ class DotStar:
             time.sleep(2)
     """
 
-    def __init__(self, clock, data, n, brightness=1.0, auto_write=True):
-        self.spi = None
+    def __init__(self, clock, data, n, *, brightness=1.0, auto_write=True):
+        self._spi = None
         try:
-            self.spi = busio.SPI(clock, MOSI=data)
-            while not self.spi.try_lock():
+            self._spi = busio.SPI(clock, MOSI=data)
+            while not self._spi.try_lock():
                 pass
-            self.spi.configure(baudrate=4000000)
+            self._spi.configure(baudrate=4000000)
         except ValueError:
             self.dpin = digitalio.DigitalInOut(data)
             self.cpin = digitalio.DigitalInOut(clock)
             self.dpin.direction = digitalio.Direction.OUTPUT
             self.cpin.direction = digitalio.Direction.OUTPUT
             self.cpin.value = False
-        self.n = n
+        self._n = n
         self.start_header_size = 4
         # Supply one extra clock cycle for each two pixels in the strip.
         self.end_header_size = n // 16
         if n % 16 != 0:
             self.end_header_size += 1
-        self.buf = bytearray(n * 4 + self.start_header_size + self.end_header_size)
-        self.end_header_index = len(self.buf) - self.end_header_size;
+        self._buf = bytearray(n * 4 + self.start_header_size + self.end_header_size)
+        self.end_header_index = len(self._buf) - self.end_header_size
 
         # Four empty bytes to start.
         for i in range(self.start_header_size):
-            self.buf[i] = 0x00
+            self._buf[i] = 0x00
         # Mark the beginnings of each pixel.
         for i in range(self.start_header_size, self.end_header_index, 4):
-            self.buf[i] = 0xff
+            self._buf[i] = 0xff
         # 0xff bytes at the end.
-        for i in range(self.end_header_index, len(self.buf)):
-            self.buf[i] = 0xff
+        for i in range(self.end_header_index, len(self._buf)):
+            self._buf[i] = 0xff
+        self._brightness = 1.0
         self.brightness = brightness
         self.auto_write = auto_write
 
@@ -98,10 +103,10 @@ class DotStar:
         self.auto_write = False
         for i in range(self.start_header_size, self.end_header_index):
             if i % 4 != 0:
-                self.buf[i] = 0
+                self._buf[i] = 0
         self.show()
-        if self.spi:
-            self.spi.deinit()
+        if self._spi:
+            self._spi.deinit()
         else:
             self.dpin.deinit()
             self.cpin.deinit()
@@ -120,7 +125,7 @@ class DotStar:
         r = 0
         g = 0
         b = 0
-        if type(value) == int:
+        if isinstance(value, int):
             r = value >> 16
             g = (value >> 8) & 0xff
             b = value & 0xff
@@ -130,10 +135,10 @@ class DotStar:
         # sheet suggests using a global brightness in the first byte, we don't
         # do that because it causes further issues with persistence of vision
         # projects.
-        self.buf[offset] = 0xff    # redundant; should already be set
-        self.buf[offset + 1] = b
-        self.buf[offset + 2] = g
-        self.buf[offset + 3] = r
+        self._buf[offset] = 0xff    # redundant; should already be set
+        self._buf[offset + 1] = b
+        self._buf[offset + 2] = g
+        self._buf[offset + 3] = r
 
     def __setitem__(self, index, val):
         if isinstance(index, slice):
@@ -154,20 +159,20 @@ class DotStar:
     def __getitem__(self, index):
         if isinstance(index, slice):
             out = []
-            for in_i in range(*index.indices(len(self.buf) // 4)):
-                out.append(tuple(self.buf[in_i * 4 + (3 - i) + self.start_header_size]
-                           for i in range(3)))
+            for in_i in range(*index.indices(len(self._buf) // 4)):
+                out.append(
+                    tuple(self._buf[in_i * 4 + (3 - i) + self.start_header_size] for i in range(3)))
             return out
         if index < 0:
             index += len(self)
-        if index >= self.n or index < 0:
+        if index >= self._n or index < 0:
             raise IndexError
         offset = index * 4
-        return tuple(self.buf[offset + (3 - i) + self.start_header_size]
+        return tuple(self._buf[offset + (3 - i) + self.start_header_size]
                      for i in range(3))
 
     def __len__(self):
-        return self.n
+        return self._n
 
     @property
     def brightness(self):
@@ -182,15 +187,15 @@ class DotStar:
         """Colors all pixels the given ***color***."""
         auto_write = self.auto_write
         self.auto_write = False
-        for i in range(len(self)):
+        for i, _ in enumerate(self):
             self[i] = color
         if auto_write:
             self.show()
         self.auto_write = auto_write
 
-    def ds_writebytes(self, buf):
+    def _ds_writebytes(self, buf):
         for b in buf:
-            for i in range(8):
+            for _ in range(8):
                 self.cpin.value = True
                 self.dpin.value = (b & 0x80)
                 self.cpin.value = False
@@ -203,20 +208,20 @@ class DotStar:
         The colors may or may not be showing after this function returns because
         it may be done asynchronously."""
         # Create a second output buffer if we need to compute brightness
-        buf = self.buf
+        buf = self._buf
         if self.brightness < 1.0:
-            buf = bytearray(self.buf)
+            buf = bytearray(self._buf)
             # Four empty bytes to start.
             for i in range(self.start_header_size):
                 buf[i] = 0x00
             for i in range(self.start_header_size, self.end_header_index):
-                buf[i] = self.buf[i] if i %4 == 0 else int(self.buf[i] * self._brightness)
+                buf[i] = self._buf[i] if i %4 == 0 else int(self._buf[i] * self._brightness)
             # Four 0xff bytes at the end.
             for i in range(self.end_header_index, len(buf)):
                 buf[i] = 0xff
 
-        if self.spi:
-            self.spi.write(buf)
+        if self._spi:
+            self._spi.write(buf)
         else:
-            self.ds_writebytes(buf)
+            self._ds_writebytes(buf)
             self.cpin.value = False

requirements.txt

@@ -1 +0,0 @@
-circuitpython-travis-build-tools