a sentence; one sentence
(short) piece of writing
「一文」 has another reading with different meanings.
一文を丁寧に書き直した。
I carefully rewrote one sentence.
冒頭の一文が読者の心を掴んだ。
The opening sentence captured the reader's heart.
たった一文を変えるだけで文章の印象が変わる。
Just by changing one sentence, the impression of the text changes.