ButlerRepoIndex

class lsst.daf.butler.ButlerRepoIndex

Bases: object

Index of all known butler repositories.

The index of butler repositories can be configured in two ways:

1. By setting the environment variable DAF_BUTLER_REPOSITORY_INDEX to the URI of a configuration file. 2. By setting the environment variable DAF_BUTLER_REPOSITORIES to the contents of the configuration file as a string.

In either case, the configuration is a simple dictionary lookup of the form:

label1: uri1
label2: uri2

and can be in YAML or JSON format. The content of the file will be cached.

Attributes Summary

index_env_var	The name of the environment variable containing the URI of the index configuration file.
repositories_env_var	The name of the environment variable containing the configuration directly as a string.

Methods Summary

get_failure_reason()	Return possible reason for failure to return repository index.
get_known_repos()	Retrieve the list of known repository labels.
get_repo_uri(label[, return_label])	Look up the label in a butler repository index.

Attributes Documentation

index_env_var: ClassVar[str] = 'DAF_BUTLER_REPOSITORY_INDEX'

The name of the environment variable containing the URI of the index configuration file.

repositories_env_var: ClassVar[str] = 'DAF_BUTLER_REPOSITORIES'

The name of the environment variable containing the configuration directly as a string.

Methods Documentation

classmethod get_failure_reason() → str

Return possible reason for failure to return repository index.

Returns:

reasonstr

If there is a problem reading the repository index, this will contain a string with an explanation. Empty string if everything worked.

Notes

The value returned is only reliable if called immediately after a failure. The most recent failure reason is reset every time an attempt is made to request a label and so the reason can be out of date.

classmethod get_known_repos() → set[str]

Retrieve the list of known repository labels.

Returns:

reposset of str

All the known labels. Can be empty if no index can be found.

classmethod get_repo_uri(label: str, return_label: bool = False) → ResourcePath

Look up the label in a butler repository index.

Parameters:

labelstr

Label of the Butler repository to look up.

return_labelbool, optional

If label cannot be found in the repository index (either because index is not defined or label is not in the index) and return_label is True then return ResourcePath(label). If return_label is False (default) then an exception will be raised instead.

Returns:

urilsst.resources.ResourcePath

URI to the Butler repository associated with the given label or default value if it is provided.

Raises:

KeyError

Raised if the label is not found in the index, or if an index is not defined, and return_label is False.

FileNotFoundError

Raised if an index is defined in the environment but it can not be found.