B '=[@s(dZddlmZddlmZddZdS)z.API for converting notebooks between versions.)versions) get_versioncCst|\}}||kr|S|tkr||kr<|d}t|j}n|d}t|j}||}|dd|krvtd||ft||Std|dS)aConvert a notebook node object to a specific version. Assumes that all the versions starting from 1 to the latest major X are implemented. In other words, there should never be a case where v1 v2 v3 v5 exist without a v4. Also assumes that all conversions can be made in one step increments between major versions and ignores minor revisions. Parameters ---------- nb : NotebookNode to_version : int Major revision to convert the notebook to. Can either be an upgrade or a downgrade. rZnbformatz+Failed to convert notebook from v%d to v%d.zACannot convert notebook to v%d because that version doesn't existN)rrZupgradeZ downgradeget ValueErrorconvert)ZnbZ to_versionversionZ version_minorZ step_versionZconvert_functionZ convertedr1lib/python3.7/site-packages/nbformat/converter.pyr s    rN)__doc__rreaderrrrrrr s