Exceptions¶

Every error raised by the package derives from MypackageError and from the closest standard-library exception.

graph TD
    E[Exception] --> M[MypackageError]
    V[ValueError] --> VE[ValidationError]
    M --> VE
    VE --> ES[EmptySeriesError]
    R[RuntimeError] --> NF[NotFittedError]
    M --> NF

exceptions ¶

Exception hierarchy for mypackage.

Every error raised by this package derives from MypackageError, so a caller can trap the whole package with a single except clause while still being able to discriminate between failure modes when it matters.

The concrete errors also inherit from the closest standard-library exception (ValueError, RuntimeError), so code written against the stdlib keeps working without importing anything from this package.

MypackageError ¶

Bases: Exception

Base class for every exception raised by mypackage.

Examples:

>>> from mypackage import EmptySeriesError, MypackageError
>>> issubclass(EmptySeriesError, MypackageError)
True

ValidationError ¶

Bases: MypackageError, ValueError

Raised when an argument fails validation.

Also a ValueError, so except ValueError still catches it.

Examples:

>>> from mypackage import moving_average
>>> try:
...     moving_average([1.0, 2.0, 3.0], window=0)
... except ValueError as err:
...     print(err)
'window' must be a positive integer, got 0

EmptySeriesError ¶

Bases: ValidationError

Raised when an operation requires at least one observation.

Examples:

>>> from mypackage import EmptySeriesError, summarize
>>> try:
...     summarize([])
... except EmptySeriesError as err:
...     print(err)
'series' must contain at least one value, got 0

NotFittedError ¶

Bases: MypackageError, RuntimeError

Raised when a stateful transform is used before it has been fitted.

Examples:

>>> from mypackage import NotFittedError, Standardize
>>> try:
...     Standardize().apply([1.0, 2.0])
... except NotFittedError as err:
...     print(err)
Standardize is not fitted; call .fit(series) first