cfel-pylint-checkers

Installation

Just pip install cfel-pylint-checkers should suffice. Then you can enable the appropriate checkers as plugins by editing your .pylintrc file, extending the load-plugins line. For example:

load-plugins=cfel_pylint_checkers.no_direct_dict_access,cfel_pylint_checkers.tango_command_dtype

Checkers

no-direct-dict-access

Enable with:

load-plugins=cfel_pylint_checkers.no_direct_dict_access

This disallows the use of dictionary access using the [] operator for reading. Meaning, this is no longer allowed:

mydict = { "foo": 3 }

print(mydict["bar"])

As you can see, this code produces an error, since we’re accessing "bar" but the mydict dictionary only contains the key "foo". You have to use .get to make this safe:

mydict = { "foo": 3 }

print(mydict.get("bar"))

Which produces None if the key doesn’t exist. You can even specify a default value:

mydict = { "foo": 3 }

print(mydict.get("bar", 0))

Mutating use of operator[] is, of course, still possible. This is fine:

mydict = { "foo": 3 }

mydict["bar"] = 4

tango-command-dtype

Enable with:

load-plugins=cfel_pylint_checkers.tango_command_dtype

This checker tests for various error conditions related to the hardware controls system Tango, specifically its Python adaptation PyTango.

For instance, the following mismatch between the dtype_in of a command and its actual type annotation is caught:

from tango.server import Device, command

class MyDevice(Device):
    @command(dtype_in=int)
    def mycommand(self, argument: str) -> None:
        pass