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Command line

Command-Line

Usage: basedpyright [options] [files...] 1

basedpyright can be run as either a language server or as a command-line tool. The command-line version allows for the following options:

Flag Description
--createstub <IMPORT> Create type stub file(s) for import
--dependencies Emit import dependency information
-h, --help Show help message
--ignoreexternal Ignore external imports for --verifytypes
--level Minimum diagnostic level (error or warning)
--outputjson Output results in JSON format
--gitlabcodequality Output results to a gitlab code quality report
--writebaseline Write new errors to the baseline file
--baselinefile <FILE> Path to the baseline file to be used 2
--baselinemode <MODE> Specify the baseline mode
-p, --project <FILE OR DIRECTORY> Use the configuration file at this location
--pythonpath <FILE> Path to the Python interpreter 3
--pythonplatform <PLATFORM> Analyze for platform (Darwin, Linux, Windows)
--pythonversion <VERSION> Analyze for version (3.3, 3.4, etc.)
--skipunannotated Skip type analysis of unannotated functions
--stats Print detailed performance stats
-t, --typeshedpath <DIRECTORY> Use typeshed type stubs at this location 4
--threads Use up to N threads to parallelize type checking 5
-v, --venvpath <DIRECTORY> Directory that contains virtual environments 6
--verbose Emit verbose diagnostics
--verifytypes <IMPORT> Verify completeness of types in py.typed package
--version Print pyright version and exit
--warnings Use exit code of 1 if warnings are reported 7
-w, --watch Continue to run and watch for changes 8
- Read file or directory list from stdin

Pyright Exit Codes

Exit Code Meaning
0 No errors reported
1 One or more errors reported
2 Fatal error occurred with no errors or warnings reported
3 Config file could not be read or parsed
4 Illegal command-line parameters specified

JSON Output

If the “--outputjson” option is specified on the command line, diagnostics are output in JSON format. The JSON structure is as follows: 

interface PyrightJsonResults {
    version: string,
    time: string,
    generalDiagnostics: Diagnostic[],
    summary: {
        filesAnalyzed: number,
        errorCount: number,
        warningCount: number,
        informationCount: number,
        timeInSec: number
    }
}

Each Diagnostic is output in the following format:

interface Diagnostic {
    file: string,
    cell?: string // if the file is a jupyter notebook
    severity: 'error' | 'warning' | 'information',
    message: string,
    rule?: string,
    range: {
        start: {
            line: number,
            character: number
        },
        end: {
            line: number,
            character: number
        }
    }
}

Diagnostic line and character numbers are zero-based.

Not all diagnostics have an associated diagnostic rule. Diagnostic rules are used only for diagnostics that can be disabled or enabled. If a rule is associated with the diagnostic, it is included in the output. If it’s not, the rule field is omitted from the JSON output.

Gitlab code quality report

the --gitlabcodequality argument will output a gitlab code quality report.

to enable this in your gitlab CI, you need to specify a path to the code quality report file to this argument, and in the artifacts section in your gitlab CI file:

basedpyright:
  script: basedpyright --gitlabcodequality report.json
  artifacts:
    reports:
      codequality: report.json

Regenerating the baseline file

if you're using baseline, as baselined errors are removed from your code, the CLI will automatically update the baseline file to remove them:

>basedpyright
updated ./.basedpyright/baseline.json with 200 errors (went down by 5)
0 errors, 0 warnings, 0 notes

the --writebaseline argument is only required if you are intentionally writing new errors to the baseline file. for more information about when to use this argument, see here.

the CLI provides two options for managing the baseline file:

when not specified

when specified

always updates the baseline file, even if new errors are added.

Option 2: --baselinemode (experimental)

Warning

--baselinemode is an experimental feature and is subject to breaking changes in the future. if you have feedback for this feature, please open an issue

Tip

for most users, we don't recommend --baselinemode as the --writebaseline flag is sufficient for most use cases. --baselinemode exists for users who want more control over how and when the baseline file is used.

--baselinemode=auto

only updates the baseline file if diagnostics have been removed and no new diagnostics have been added.

Note

this is the same as not specifying --baselinemode or --writebaseline when running locally. you only need to specify --baselinemode=auto explicitly if you want to disable the default --baselinemode=never behavior in CI environments

--baselinemode=lock

never writes to the baseline file, even if no new diagnostics have surfaced, and instead exits with a non-zero exit code if the baseline file needs to be updated. useful in CI environments when you want to ensure that the baseline file is up-to-date.

Note

basedpyright already defaults to this mode if running in CI. you only need to specify this explicitly if your CI environment is not detected for some reason, or if you want this behavior locally (such as a prek hook).

you can think of it like a lockfile. you don't want the baseline file to contain errors that don't exist anymore because:

  • when other contributors run basedpyright, it could update the baseline file to remove errors in code they have not changed, which is unexpected and leads to confusion
  • it would make it possible to unintentionally re-introduce the error in the future without it being flagged by basedpyright

--baselinemode=discard

reads the baseline file but never updates it, even if it needs to be updated. exits with code 0 unless new diagnostics have surfaced.

  1. If specific files are specified on the command line, it overrides the files or directories specified in the pyrightconfig.json or pyproject.toml file. ↩

  2. Defaults to ./.basedpyright/baseline.json ↩

  3. This option is the same as the language server setting python.pythonPath. It cannot be used with --venvpath. The --pythonpath option is recommended over --venvpath in most cases. For more details, refer to the import resolution documentation. ↩

  4. Pyright has built-in typeshed type stubs for Python stdlib functionality. To use a different version of typeshed type stubs, specify the directory with this option. ↩

  5. This feature is experimental. If thread count is > 1, multiple copies of pyright are executed in parallel to type check files in a project. If no thread count is specified, the thread count is based on the number of available logical processors (if at least 4) or 1 (if less than 4). ↩

  6. --venvpath is discouraged in basedpyright. see here for more info.

    This option is the same as the language server setting python.venvPath. It used in conjunction with configuration file, which can refer to different virtual environments by name. For more details, refer to the configuration and import resolution documentation. This allows a common config file to be checked in to the project and shared by everyone on the development team without making assumptions about the local paths to the venv directory on each developer’s computer. ↩

  7. --warnings is equivalent to failOnWarnings, which is enabled by default in basedpyright, meaning this option is redundant unless you explicitly disable failOnWarnings. see here for more information about this decision ↩

  8. When running in watch mode, pyright will reanalyze only those files that have been modified. These “deltas” are typically much faster than the initial analysis, which needs to analyze all files in the source tree. ↩