From: James Bunton <jamesbunton@delx.net.au>
Date: Wed, 22 Feb 2017 12:08:44 +0000 (+1100)
Subject: Port to Python3, run with only Python+Node (no libs)
X-Git-Url: https://code.delx.au/youtube-cgi/commitdiff_plain/7697735a88f01ad5d61f50663e4221e75fafc3ca

Port to Python3, run with only Python+Node (no libs)
---

diff --git a/README.md b/README.md
index 75a57a3..6c2ae14 100644
--- a/README.md
+++ b/README.md
@@ -4,8 +4,7 @@ YouTubeCgi is a simple tool to download videos from YouTube. It is able to fetch
 
 ## Requirements
 
-- python 2.7
-- python-lxml
+- python 3
 - nodejs 4+
 
 ## CLI Usage
diff --git a/youtube.cgi b/youtube.cgi
index 1a80bf7..c0b5e99 100755
--- a/youtube.cgi
+++ b/youtube.cgi
@@ -1,21 +1,18 @@
-#!/usr/bin/python2
+#!/usr/bin/env python3
 
-from __future__ import division
-
-import cookielib
 import cgi
+import html.parser
+import http.cookiejar
 import json
-from lxml import html
 import os
 import re
-import resource
 import shutil
 import subprocess
 import sys
 import time
-import urllib
-import urllib2
-import urlparse
+import urllib.error
+import urllib.parse
+import urllib.request
 
 
 MAX_MEMORY_BYTES = 128 * 1024*1024
@@ -41,13 +38,13 @@ class VideoUnavailable(Exception):
 
 def print_form(url="", msg=""):
     script_url = "http://%s%s" % (os.environ["HTTP_HOST"], os.environ["REQUEST_URI"])
-    sys.stdout.write("Content-Type: application/xhtml+xml\r\n\r\n")
+    sys.stdout.write("Content-Type: text/html\r\n\r\n")
     sys.stdout.write("""
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<!DOCTYPE html>
+<html>
 <head>
     <title>delx.net.au - YouTube Scraper</title>
-    <link rel="stylesheet" type="text/css" href="/style.css"/>
+    <link rel="stylesheet" type="text/css" href="/style.css">
     <style type="text/css">
         input[type="text"] {
             width: 100%;
@@ -74,8 +71,8 @@ def print_form(url="", msg=""):
 </html>
 """.replace("{0}", msg).replace("{1}", url).replace("{2}", script_url))
 
-cookiejar = cookielib.CookieJar()
-urlopener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookiejar))
+cookiejar = http.cookiejar.CookieJar()
+urlopener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cookiejar))
 referrer = ""
 
 def urlopen(url, offset=None):
@@ -85,7 +82,7 @@ def urlopen(url, offset=None):
         url = "https://www.youtube.com" + url
 
     global referrer
-    req = urllib2.Request(url)
+    req = urllib.request.Request(url)
     if not referrer:
         referrer = url
     else:
@@ -98,7 +95,7 @@ def urlopen(url, offset=None):
 
     res = urlopener.open(req)
 
-    content_range = res.info().getheader("Content-Range")
+    content_range = res.getheader("Content-Range")
     if content_range:
         tokens = content_range.split()
         assert tokens[0] == "bytes"
@@ -106,26 +103,24 @@ def urlopen(url, offset=None):
         assert start == offset
     return res
 
-def parse_url(url):
+def parse_url(url, parser):
     f = urlopen(url)
-    doc = html.parse(f, html.HTMLParser(encoding="utf-8", recover=True))
+    parser.feed(f.read().decode("utf-8"))
+    parser.close()
     f.close()
-    return doc
 
 def append_to_qs(url, params):
-    r = list(urlparse.urlsplit(url))
-    qs = urlparse.parse_qs(r[3])
+    r = list(urllib.parse.urlsplit(url))
+    qs = urllib.parse.parse_qs(r[3])
     qs.update(params)
-    r[3] = urllib.urlencode(qs, True)
-    url = urlparse.urlunsplit(r)
+    r[3] = urllib.parse.urlencode(qs, True)
+    url = urllib.parse.urlunsplit(r)
     return url
 
-def get_player_config(doc):
+def get_player_config(scripts):
     player_config = None
-    for script in doc.xpath("//script"):
-        if not script.text:
-            continue
-        for line in script.text.split("\n"):
+    for script in scripts:
+        for line in script.split("\n"):
             s = "ytplayer.config = {"
             if s in line:
                 p1 = line.find(s) + len(s) - 1
@@ -152,7 +147,10 @@ def find_func_name(script):
     return func_name
 
 def decode_signature(js_url, signature):
-    script = urlopen(js_url).read()
+    f = urlopen(js_url)
+    script = f.read().decode("utf-8")
+    f.close()
+
     func_name = find_func_name(script)
 
     params = {
@@ -161,7 +159,7 @@ def decode_signature(js_url, signature):
         "code": json.dumps(extract_js(script)),
     }
     p = subprocess.Popen(
-        "nodejs",
+        "node",
         shell=True,
         close_fds=True,
         stdin=subprocess.PIPE,
@@ -196,10 +194,10 @@ def decode_signature(js_url, signature):
         console.log(sandbox.transformed_signature);
     """ % params)
 
-    p.stdin.write(js_decode_script)
+    p.stdin.write(js_decode_script.encode("utf-8"))
     p.stdin.close()
 
-    transformed_signature = p.stdout.read().strip()
+    transformed_signature = p.stdout.read().decode("utf-8").strip()
     if p.wait() != 0:
         raise Exception("js failed to execute: %d" % p.returncode)
 
@@ -213,11 +211,11 @@ def get_best_video(player_config):
     best_quality = None
     best_extension = None
     for url_data in url_data_list:
-        url_data = urlparse.parse_qs(url_data)
+        url_data = urllib.parse.parse_qs(url_data)
         mimetype = url_data["type"][0].split(";")[0]
         quality = url_data["quality"][0]
 
-        if url_data.has_key("stereo3d"):
+        if "stereo3d" in url_data:
             continue
         if quality not in QUALITIES:
             continue
@@ -255,32 +253,73 @@ def sanitize_filename(filename):
         .replace("\0", " ")
     )
 
-def get_video_url(doc):
-    unavailable = doc.xpath("//div[@id='unavailable-message']/text()")
-    if unavailable:
-        raise VideoUnavailable(unavailable[0].strip())
-
-    player_config = get_player_config(doc)
+def get_video_url(page):
+    player_config = get_player_config(page.scripts)
     if not player_config:
-        raise VideoUnavailable("Could not find video URL")
+        raise VideoUnavailable(page.unavailable_message or "Could not find video URL")
 
     video_url, extension = get_best_video(player_config)
     if not video_url:
         return None, None
 
-    title = doc.xpath("/html/head/title/text()")[0]
-    filename = sanitize_filename(title)
+    filename = sanitize_filename(page.title)
     filename += "." + extension
 
     return video_url, filename
 
+class YouTubeVideoPageParser(html.parser.HTMLParser):
+    def __init__(self):
+        super().__init__()
+        self.title = None
+        self.unavailable_message = None
+        self.scripts = []
+
+    def handle_starttag(self, tag, attrs):
+        attrs = dict(attrs)
+        self._handle_title(tag, attrs)
+        self._handle_unavailable_message(tag, attrs)
+        self._handle_script(tag, attrs)
+
+    def handle_endtag(self, tag):
+        self.handle_data = self._ignore_data
+
+    def _ignore_data(self, _):
+        pass
+
+    def _handle_title(self, tag, attrs):
+        if tag == "title":
+            self.handle_data = self._handle_title_data
+
+    def _handle_title_data(self, data):
+        self.title = data.strip()
+
+    def _handle_unavailable_message(self, tag, attrs):
+        if attrs.get("id", None) == "unavailable-message":
+            self.handle_data = self._handle_unavailable_message_data
+
+    def _handle_unavailable_message_data(self, data):
+        self.unavailable_message = data.strip()
+
+    def _handle_script(self, tag, attrs):
+        if tag == "script":
+            self.handle_data = self._handle_script_data
+
+    def _handle_script_data(self, data):
+        if data:
+            self.scripts.append(data)
+
 def write_video(filename, video_data):
-    httpinfo = video_data.info()
-    encoded_filename = urllib.quote(filename.encode("utf-8"))
-    sys.stdout.write("Content-Disposition: attachment; filename*=UTF-8''%s\r\n" % encoded_filename)
-    sys.stdout.write("Content-Length: %s\r\n" % httpinfo.getheader("Content-Length"))
-    sys.stdout.write("\r\n")
-    shutil.copyfileobj(video_data, sys.stdout)
+    quoted_filename = urllib.parse.quote(filename.encode("utf-8"))
+    sys.stdout.buffer.write(
+        b"Content-Disposition: attachment; filename*=UTF-8''{0}\r\n"
+        .replace(b"{0}", quoted_filename.encode("utf-8"))
+    )
+    sys.stdout.buffer.write(
+        b"Content-Length: {0}\r\n"
+        .replace(b"{0}", video_data.getheader("Content-Length").encode("utf-8"))
+    )
+    sys.stdout.buffer.write(b"\r\n")
+    shutil.copyfileobj(video_data, sys.stdout.buffer)
     video_data.close()
 
 def cgimain():
@@ -292,22 +331,24 @@ def cgimain():
         return
 
     try:
-        doc = parse_url(url)
-        video_url, filename = get_video_url(doc)
+        page = YouTubeVideoPageParser()
+        parse_url(url, page)
+        video_url, filename = get_video_url(page)
         video_data = urlopen(video_url)
-        write_video(filename, video_data)
-    except VideoUnavailable, e:
+    except VideoUnavailable as e:
         print_form(
             url=url,
-            msg="<p class='error'>Sorry, there was an error: %s</p>" % cgi.escape(e.message)
+            msg="<p class='error'>Sorry, there was an error: %s</p>" % cgi.escape(e.args[0])
         )
-    except Exception, e:
+    except Exception as e:
         print_form(
             url=url,
             msg="<p class='error'>Sorry, there was an error. Check your URL?</p>"
         )
         return
 
+    write_video(filename, video_data)
+
 def pp_size(size):
     suffixes = ["", "KiB", "MiB", "GiB"]
     for i, suffix in enumerate(suffixes):
@@ -348,43 +389,44 @@ def copy_with_progress(content_length, infile, outfile):
 
     # Newline at the end
     print_status()
-    print
+    print()
 
 def main():
     try:
         url = sys.argv[1]
     except:
-        print >>sys.stderr, "Usage: %s http://youtube.com/watch?v=FOOBAR" % sys.argv[0]
+        print("Usage: %s http://youtube.com/watch?v=FOOBAR" % sys.argv[0], file=sys.stderr)
         sys.exit(1)
 
-    doc = parse_url(url)
-    video_url, filename = get_video_url(doc)
-    print "Downloading", filename.encode("utf-8")
+    page = YouTubeVideoPageParser()
+    parse_url(url, page)
+    video_url, filename = get_video_url(page)
+    print("Downloading", filename)
 
-    outfile = open(filename, "a")
+    outfile = open(filename, "ab")
     offset = outfile.tell()
     if offset > 0:
-        print "Resuming download from", pp_size(offset)
+        print("Resuming download from", pp_size(offset))
     total_size = None
 
     while True:
         try:
             video_data = urlopen(video_url, offset)
-        except urllib2.HTTPError, e:
+        except urllib.error.HTTPError as e:
             if e.code == 416:
-                print "File is complete!"
+                print("File is complete!")
                 break
             else:
                 raise
 
-        content_length = int(video_data.info().getheader("Content-Length"))
+        content_length = int(video_data.getheader("Content-Length"))
         if total_size is None:
             total_size = content_length
 
         try:
             copy_with_progress(content_length, video_data, outfile)
-        except IOError, e:
-            print
+        except IOError as e:
+            print()
 
         video_data.close()
         if outfile.tell() != total_size:
@@ -392,7 +434,7 @@ def main():
             offset = outfile.tell()
             if old_offset == offset:
                 time.sleep(1)
-            print "Restarting download from", pp_size(offset)
+            print("Restarting download from", pp_size(offset))
         else:
             break
 
@@ -400,13 +442,12 @@ def main():
 
 
 if __name__ == "__main__":
-### resource.setrlimit(resource.RLIMIT_AS, (MAX_MEMORY_BYTES, MAX_MEMORY_BYTES))
-    if os.environ.has_key("SCRIPT_NAME"):
+    if "SCRIPT_NAME" in os.environ:
         cgimain()
     else:
         try:
             main()
         except KeyboardInterrupt:
-            print "\nExiting..."
+            print("\nExiting...")
             sys.exit(1)
 
