How to fix vertical text filling in PDF?

pip install pypdf

#!/usr/bin/env python3
"""
fix_rotated_pdf_form.py

Flattens page rotation in a PDF form so filled-in text renders horizontally
instead of sideways. Layout, field names, and values are preserved.

Usage:
    python fix_rotated_pdf_form.py input.pdf
    python fix_rotated_pdf_form.py input.pdf -o output.pdf

Requires: pypdf  ->  pip install pypdf
"""
import argparse
import sys

try:
    from pypdf import PdfReader, PdfWriter, Transformation
    from pypdf.generic import (
        NameObject, NumberObject, ArrayObject, FloatObject,
        IndirectObject, BooleanObject,
    )
except ImportError:
    sys.exit("pypdf is required. Install it with:  pip install pypdf")


def _resolve(obj):
    return obj.get_object() if isinstance(obj, IndirectObject) else obj


def flatten_rotation(src_path, out_path):
    reader = PdfReader(src_path)
    writer = PdfWriter()
    writer.append(reader)

    changed_pages = 0

    for page in writer.pages:
        rot = int(page.get("/Rotate") or 0) % 360
        if rot == 0:
            continue

        box = [float(v) for v in page.mediabox]
        w = box[2] - box[0]
        h = box[3] - box[1]

        # Matrix that reproduces the visual rotation in un-rotated page space.
        if rot == 90:
            ctm = (0, -1, 1, 0, 0, w)
            new_w, new_h = h, w
        elif rot == 270:
            ctm = (0, 1, -1, 0, h, 0)
            new_w, new_h = h, w
        elif rot == 180:
            ctm = (-1, 0, 0, -1, w, h)
            new_w, new_h = w, h
        else:
            continue  # non-orthogonal rotation; skip safely

        page.add_transformation(Transformation(ctm))
        page.mediabox.lower_left = (0, 0)
        page.mediabox.upper_right = (new_w, new_h)
        if "/CropBox" in page:
            del page[NameObject("/CropBox")]
        page[NameObject("/Rotate")] = NumberObject(0)

        a, b, c, d, e, f = ctm

        def tx(x, y):
            return (a * x + c * y + e, b * x + d * y + f)

        annots = _resolve(page.get("/Annots")) or []
        for ann in annots:
            o = ann.get_object()
            if o.get("/Subtype") != "/Widget":
                continue
            r = [float(v) for v in o["/Rect"]]
            pts = [tx(r[0], r[1]), tx(r[2], r[3]), tx(r[0], r[3]), tx(r[2], r[1])]
            xs = [p[0] for p in pts]
            ys = [p[1] for p in pts]
            o[NameObject("/Rect")] = ArrayObject([
                FloatObject(min(xs)), FloatObject(min(ys)),
                FloatObject(max(xs)), FloatObject(max(ys)),
            ])
            mk = o.get("/MK")
            if mk is not None:
                mk = mk.get_object()
                if "/R" in mk:
                    mk[NameObject("/R")] = NumberObject(0)
            if "/AP" in o:
                del o[NameObject("/AP")]  # drop stale appearance

        changed_pages += 1

    acro = writer._root_object.get("/AcroForm")
    if acro is not None:
        acro = acro.get_object()
        acro[NameObject("/NeedAppearances")] = BooleanObject(True)

    with open(out_path, "wb") as fh:
        writer.write(fh)

    return changed_pages


def main():
    ap = argparse.ArgumentParser(
        description="Flatten page rotation in a PDF form so filled text is horizontal."
    )
    ap.add_argument("input", help="Path to the rotated PDF form")
    ap.add_argument("-o", "--output", help="Output path (default: <input>_fixed.pdf)")
    args = ap.parse_args()

    out = args.output or (args.input.rsplit(".", 1)[0] + "_fixed.pdf")
    n = flatten_rotation(args.input, out)
    if n:
        print(f"Fixed {n} rotated page(s). Saved: {out}")
    else:
        print(f"No rotated pages found; nothing to change. Copy saved: {out}")


if __name__ == "__main__":
    main()

# Creates LDSS-4411_fixed.pdf next to the input
python fix_rotated_pdf_form.py LDSS-4411.pdf

# Or choose your own output name
python fix_rotated_pdf_form.py LDSS-4411.pdf -o LDSS-4411_fixed.pdf

#!/usr/bin/env bash
# Usage: ./fix_pdf.sh input.pdf [output.pdf]
set -euo pipefail

if [ $# -lt 1 ]; then
  echo "Usage: $0 input.pdf [output.pdf]"
  exit 1
fi

IN="$1"
OUT="${2:-${1%.pdf}_fixed.pdf}"

# Ensure pypdf is available
python3 -c "import pypdf" 2>/dev/null || pip install --quiet pypdf

# Run the fixer (expects fix_rotated_pdf_form.py in the same folder)
DIR="$(cd "$(dirname "$0")" && pwd)"
python3 "$DIR/fix_rotated_pdf_form.py" "$IN" -o "$OUT"

echo "Saved: $OUT"

./fix_pdf.sh LDSS-4411.pdf

python3 - <<'PY'
from pypdf import PdfReader
r = PdfReader("LDSS-4411_fixed.pdf")
for i, p in enumerate(r.pages):
    print(f"page {i}: /Rotate = {p.get('/Rotate')}")
PY