issue with html5lib

test.py

import bleach

sample_text = """<button class="navbar-toggle collapsed" data-target=".navbar-collapse" data-toggle="collapse" type="button">
	<span class="sr-only">Toggle navigation</span>
	<span class="icon-bar"></span>
	<span class="icon-bar"></span>
	<span class="icon-bar"></span>
  </button>"""
  
tags_ok = [ 'button', 'span', ]
attributes_ok = [ 'button', 'span', ]

attributes_ok = {
    '*': ['class', 'data-toggle', 'data-target', 'type'],
}

def clean_text( text ):
    text = bleach.clean( text, tags=tags_ok, attributes=attributes_ok, strip=True, strip_comments=False )
    return text


for i in range( 1, 10 ):
    sample_text = clean_text( sample_text )
    print "*" * 10
    print sample_text