Configuration file location

Before running the linter, you need to supply configuration in a file, in INI format. Import Linter will look in the current directory for one of the following files:

  • setup.cfg
  • .importlinter

(Different filenames / locations can be specified as a command line argument, see below.)

Top level configuration

Your file must contain an importlinter section providing top-level (i.e. non-contract based) configuration:

# Required:
root_package = mypackage
# Optional:
include_external_packages = True


  • root_package: The name of the top-level Python package to validate. This package must be importable: usually this means it is has been installed using pip, or it’s in the current directory. (Required.)
  • include_external_packages: Whether to include external packages when building the import graph (see the Grimp build_graph documentation for more details). This is not currently used by any built in contracts, but it could be used by a custom contract type that wanted to enforce rules relating to packages not in the root package (i.e. in the Python standard library, or in third party libraries). (Optional.)


Additionally, you will want to include one or more contract configurations. These take the following form:

name = Contract One
type = some_contract_type
(additional options)

name = Contract Two
type = another_contract_type
(additional options)

Notice each contract has its own INI section, which begins importlinter:contract: and ends in an arbitrary, unique code (in this example, the codes are 1 and 2). These codes are purely to adhere to the INI format, which does not allow duplicate section names.

Every contract will always have the following key/value pairs:

  • name: A human-readable name for the contract.
  • type: The type of contract to use (see Contract types.)

Each contract type defines additional options that you supply here.

Running the linter

Import Linter provides a single command: lint-imports.

Running this will check that your project adheres to the contracts you’ve defined.


  • --config: The configuration file to use. If not supplied, Import Linter will look for setup.cfg or .importlinter in the current directory. (Optional.)

Default usage:


Using a different filename or location:

lint-imports --config path/to/alternative-config.ini