ó ‹'=[c@s3dZddlmZddlmZd„ZdS(s.API for converting notebooks between versions.i(tversions(t get_versioncCsÉt|ƒ\}}||kr"|S|tkrµ||krT|d}t|j}n|d}t|j}||ƒ}|jddƒ|kr¨td||fƒ‚nt||ƒStd|ƒ‚dS(sConvert 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. itnbformats+Failed to convert notebook from v%d to v%d.sACannot convert notebook to v%d because that version doesn't existN(RRtupgradet downgradetgett ValueErrortconvert(tnbt to_versiontversiont version_minort step_versiontconvert_functiont converted((s1lib/python2.7/site-packages/nbformat/converter.pyR s        N(t__doc__tRtreaderRR(((s1lib/python2.7/site-packages/nbformat/converter.pyts