mafw.scaffold.errors

Typed error hierarchy for the project scaffolding service.

Every failure of the mafw init generation service is reported through a subclass of mafw.scaffold.errors.ScaffoldError. The command line layer maps each error to a non-zero exit code and a specific message, so that a scientist always receives a clear reason for a failed generation instead of a half-written project.

Added in version 2.4.

Exceptions

DestinationNotEmptyError	Raised when the resolved destination directory already contains entries.
GenerationError	Raised when rendering or writing the project fails partway through.
InvalidEmailError	Raised when the supplied author e-mail address is not well formed.
InvalidNameError	Raised when the requested project name cannot become a valid package name.
MissingTemplateError	Raised when the bundled canonical template cannot be located.
MissingValueError	Raised in non-interactive mode when a required value was not supplied.
NameCollisionError	Raised when the derived import name clashes with a reserved name.
ScaffoldError	Base class for every error raised by the scaffolding service.

exception mafw.scaffold.errors.DestinationNotEmptyError

Bases: ScaffoldError

Raised when the resolved destination directory already contains entries.

The service never overwrites an existing, non-empty project; the user must pick an empty or non-existent destination instead.

exception mafw.scaffold.errors.GenerationError

Bases: ScaffoldError

Raised when rendering or writing the project fails partway through.

The service rolls back to the exact pre-run filesystem state before raising this error, so no partially generated project is ever left behind.

exception mafw.scaffold.errors.InvalidEmailError

Bases: ScaffoldError

Raised when the supplied author e-mail address is not well formed.

A malformed e-mail (for example one missing the @ or the domain part) produces invalid pyproject.toml metadata that makes the build backend fail, so it is rejected up front with a clear message.

exception mafw.scaffold.errors.InvalidNameError

Bases: ScaffoldError

Raised when the requested project name cannot become a valid package name.

This covers an empty or over-long name, a name that does not match the Python package identifier grammar, and a name that contains a path separator or a ./.. path component (a traversal attempt).

exception mafw.scaffold.errors.MissingTemplateError

Bases: ScaffoldError

Raised when the bundled canonical template cannot be located.

This indicates that the template package data was not shipped with the installed MAFw distribution; it is an installation problem rather than a user input problem.

exception mafw.scaffold.errors.MissingValueError

Bases: ScaffoldError

Raised in non-interactive mode when a required value was not supplied.

In non-interactive mode the service never prompts, so a missing required value is a hard error that names each missing value.

exception mafw.scaffold.errors.NameCollisionError

Bases: ScaffoldError

Raised when the derived import name clashes with a reserved name.

The clash is either a Python (hard or soft) keyword or a top-level module of the standard library; importing such a package would shadow or be shadowed by existing names, so generation is refused.

exception mafw.scaffold.errors.ScaffoldError

Bases: Exception

Base class for every error raised by the scaffolding service.

Catching mafw.scaffold.errors.ScaffoldError is enough to intercept all expected failure modes of the generation service (invalid names, unsafe destinations, missing template resources, and so on).