openpyxl.preserve.drawings

Charts and images added in-session become NEW drawing/chart/media parts through the lifecycle engine — the stock writer's own serialization, never a re-render of preserved bytes.

Three shapes, in increasing contact with original bytes:

ADDED sheet: the stock worksheet writer already emitted <drawing r:id>; this module supplies the parts and fills the rel.
LOADED sheet, no drawing machinery: a fresh drawing part plus ONE <drawing r:id> element spliced into the sheet at its schema position.
LOADED sheet, existing drawing: new anchors appended INTO the original drawing part — only when that part is anchor-only; anything else refuses.

Preserved drawing parts are never re-serialized: appends are byte insertions before the closing tag, with namespaces declared on the inserted anchors themselves.

`CHART_CT`

attributeCHART_CT

= 'application/vnd.openxmlformats-officedocument.drawingml.chart+xml'

`CHART_REL_TYPE`

attributeCHART_REL_TYPE

= REL_NS + '/chart'

`DRAWING_CT`

attributeDRAWING_CT

= 'application/vnd.openxmlformats-officedocument.drawing+xml'

`DRAWING_REL_TYPE`

attributeDRAWING_REL_TYPE

= REL_NS + '/drawing'

`IMAGE_REL_TYPE`

attributeIMAGE_REL_TYPE

= REL_NS + '/image'

`REL_NS`

attributeREL_NS

= 'http://schemas.openxmlformats.org/officeDocument/2006/relationships'

`SHEET_DRAWING_NS`

attributeSHEET_DRAWING_NS

= 'http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing'

`plan_added_sheet_drawing`

funcplan_added_sheet_drawing(workbook, ws, part_plan, names, rel_entries)

Charts/images on an ADDED sheet: the stock writer emitted <drawing r:id> into the fresh sheet payload with an empty rel Target; supply the drawing/chart/media parts and fill the target. Returns the updated sheet rel entries.

paramworkbook

paramws

parampart_plan

paramnames

paramrel_entries

`plan_drawing_append`

funcplan_drawing_append(workbook, ws, part_plan, names, drawing_part, original, existing_rels, charts, images)

Charts/images on a LOADED sheet whose drawing already exists: new anchors appended INTO the original drawing bytes (original may already carry this save's shift patches) — only when that drawing is anchor-only. Returns the new drawing payload.

paramworkbook

paramws

parampart_plan

paramnames

paramdrawing_part

paramoriginal

paramexisting_rels

paramcharts

paramimages

`plan_fresh_drawing`

funcplan_fresh_drawing(workbook, ws, part_plan, names, sheet_part, original_sheet_rels, charts, images)

Charts/images on a LOADED sheet with no drawing machinery: a fresh drawing part via the engine plus ONE spliced element. Returns the <drawing r:id> bytes for the region splice.

paramworkbook

paramws

parampart_plan

paramnames

paramsheet_part

paramoriginal_sheet_rels

paramcharts

paramimages

openpyxl.preserve.drawings

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