EmDashify — Em Dashes Made Easy

The Python library you think you'll never need—until you use it more than the ones you do.

Why?

ChatGPT, Claude, and other large language models often use the em dash (—) when answering users. It's become especially noticeable in AI-generated responses: Pew Research Center found that em dashes appeared about twice as often in the English-language web text it studied as in 2023. Of course, the em dash predates AI—it's ordinary punctuation, not proof that a text was AI-written.

Yet most QWERTY keyboards have a - key, not a dedicated — key. EmDashify lets you type -- and turn it into a proper em dash in text, Markdown, or Word documents. No AI needed. Just punctuation.

Quick start

pip install emdashify
emdashify "Hello -- world"
# Hello—world

from emdashify import convert

convert("Hello -- world")                  # 'Hello—world'
convert("hello--world")                    # 'hello—world'
convert("Hello -- world", compact=False)   # 'Hello — world'

Edit files in place (with a backup)

Prefer updating the file directly? Add --in-place to convert it safely, keeping the unmodified original as a .bak file:

emdashify --file notes.md --in-place     # saves notes.md.bak
emdashify --file draft.docx --in-place   # saves draft.docx.bak (requires [word])

from emdashify import convert_in_place

convert_in_place("notes.md")  # True if changed, False if already clean

Existing backups are never overwritten. No backup is created if the document is already clean. Symlinks are not edited in place, and writing a file over itself with --output is rejected.

Word documents (.docx)

Convert an entire Word document, including paragraphs, tables, headers and footers, without flattening text formatting. Install the optional Word extra:

pip install "emdashify[word]"
emdashify --file draft.docx --output draft-fixed.docx
emdashify --file draft.docx --check

from emdashify import convert_docx

convert_docx("draft.docx", "draft-fixed.docx")

By default, the source file is untouched; use --in-place for an explicit backup-protected update. Word support is for .docx, not legacy .doc. Review complex documents with tracked changes or advanced Word fields after conversion.

Text and Markdown files

emdashify --file notes.md --diff
emdashify --file notes.md --output notes-fixed.md
emdashify --file notes.md --check

Compact by default: both word--word and word -- word become word—word. Flags (--help), dates, and --- stay unchanged; Markdown code blocks are protected. Use --spaced in the CLI (or compact=False in Python) to retain the former spaced style.

Requires Python 3.10+. For development or publishing, see release instructions.

License

BSD-3-Clause-Attribution. Redistributing EmDashify requires retaining license notices and this acknowledgment:

This product includes software developed by edujbarrios (https://github.com/edujbarrios/EmDashify).