webbrowser.open("127.0.0.1:8080") opens page in IE even if default system browser is Chrome.

See also #8232

Also, since you stated that this is a regression -- what was the last version you saw this work in?

If you want it to open it with the default browser you have to specify the protocol (e.g. webbrowser.open("http://127.0.0.1:8080/")).
I don't know exactly why webbrowser decides to open webbrowser.open("127.0.0.1:8080") with IE, but the behavior seems consistent in all the versions, so it's not a regression.

2.5 threw exception

webbrowser.open("%s:%s" % (HOST,PORT))
  File "C:\Python25\lib\webbrowser.py", line 61, in open
    if browser.open(url, new, autoraise):
  File "C:\Python25\lib\webbrowser.py", line 518, in open
    os.startfile(url)
WindowsError: [Error -2147217406] Windows Error 0x80041002: '127.0.0.1:8080'


I do not mind if new Python would handle this exception correctly, but it doesn't launching wrong browser. If I specify "http://" prefix - the Chrome launched as expected. Note that if "127.0.0.1:8080" is executed from shell (search menu or run dialog) - IE is not started by Vista.