| """HTML -> greppable plain text. Pure stdlib: the task images have no bs4 and no internet to get it. |
| |
| Whitespace inside <pre>/<code> is preserved -- these documents carry their worked examples in code |
| blocks, and a collapsed one ("mbarrier_init(&bar,1);// Initialize barrier") is unreadable. |
| """ |
| import re |
| import sys |
| from html.parser import HTMLParser |
|
|
| DROP = {"script", "style", "nav", "head", "noscript", "svg", "form"} |
| BLOCK = {"p", "div", "li", "tr", "br", "section", "article"} |
| HEAD = {"h1", "h2", "h3", "h4", "h5", "h6"} |
|
|
|
|
| class T(HTMLParser): |
| def __init__(self): |
| super().__init__(convert_charrefs=True) |
| self.out, self.skip, self.pre = [], 0, 0 |
|
|
| def handle_starttag(self, tag, attrs): |
| if tag in DROP: |
| self.skip += 1 |
| elif tag in ("pre", "code"): |
| if tag == "pre": |
| self.out.append("\n") |
| self.pre += 1 |
| elif self.pre: |
| if tag == "br": |
| self.out.append("\n") |
| elif tag in HEAD: |
| self.out.append("\n\n### ") |
| elif tag in BLOCK: |
| self.out.append("\n") |
| elif tag in ("td", "th"): |
| self.out.append(" ") |
|
|
| def handle_endtag(self, tag): |
| if tag in DROP and self.skip: |
| self.skip -= 1 |
| elif tag in ("pre", "code"): |
| if self.pre: |
| self.pre -= 1 |
| if tag == "pre": |
| self.out.append("\n") |
| elif not self.pre and tag in HEAD | {"table"}: |
| self.out.append("\n") |
|
|
| def handle_data(self, d): |
| if self.skip: |
| return |
| if self.pre: |
| self.out.append(d) |
| elif d.strip(): |
| self.out.append(d) |
|
|
|
|
| def convert(src): |
| p = T() |
| p.feed(src) |
| t = "".join(p.out) |
| |
| lines = [] |
| for ln in t.splitlines(): |
| lines.append(ln if ln[:1] in (" ", "\t") else re.sub(r"[ \t]{2,}", " ", ln).rstrip()) |
| t = "\n".join(lines) |
| return re.sub(r"\n{3,}", "\n\n", t).strip() + "\n" |
|
|
|
|
| if __name__ == "__main__": |
| sys.stdout.write(convert(open(sys.argv[1], encoding="utf-8", errors="ignore").read())) |
|
|
