@ -16,7 +16,11 @@ except ImportError, e:
' The soupsieve package is not installed. CSS selectors cannot be used. '
)
from bs4 . dammit import EntitySubstitution
from bs4 . formatter import (
Formatter ,
HTMLFormatter ,
XMLFormatter ,
)
DEFAULT_OUTPUT_ENCODING = " utf-8 "
PY3K = ( sys . version_info [ 0 ] > 2 )
@ -42,6 +46,11 @@ def _alias(attr):
class NamespacedAttribute ( unicode ) :
def __new__ ( cls , prefix , name , namespace = None ) :
if not name :
# This is the default namespace. Its name "has no value"
# per https://www.w3.org/TR/xml-names/#defaulting
name = None
if name is None :
obj = unicode . __new__ ( cls , prefix )
elif prefix is None :
@ -99,138 +108,71 @@ class ContentMetaAttributeValue(AttributeValueWithCharsetSubstitution):
return match . group ( 1 ) + encoding
return self . CHARSET_RE . sub ( rewrite , self . original_value )
class HTMLAwareEntitySubstitution ( EntitySubstitution ) :
""" Entity substitution rules that are aware of some HTML quirks.
Specifically , the contents of < script > and < style > tags should not
undergo entity substitution .
Incoming NavigableString objects are checked to see if they ' re the
direct children of a < script > or < style > tag .
"""
cdata_containing_tags = set ( [ " script " , " style " ] )
preformatted_tags = set ( [ " pre " ] )
preserve_whitespace_tags = set ( [ ' pre ' , ' textarea ' ] )
@classmethod
def _substitute_if_appropriate ( cls , ns , f ) :
if ( isinstance ( ns , NavigableString )
and ns . parent is not None
and ns . parent . name in cls . cdata_containing_tags ) :
# Do nothing.
return ns
# Substitute.
return f ( ns )
@classmethod
def substitute_html ( cls , ns ) :
return cls . _substitute_if_appropriate (
ns , EntitySubstitution . substitute_html )
class PageElement ( object ) :
""" Contains the navigational information for some part of the page
( either a tag or a piece of text ) """
def setup ( self , parent = None , previous_element = None , next_element = None ,
previous_sibling = None , next_sibling = None ) :
""" Sets up the initial relations between this element and
other elements . """
self . parent = parent
@classmethod
def substitute_xml ( cls , ns ) :
return cls . _substitute_if_appropriate (
ns , EntitySubstitution . substitute_xml )
self . previous_element = previous_element
if previous_element is not None :
self . previous_element . next_element = self
class Formatter ( object ) :
""" Contains information about how to format a parse tree. """
# By default, represent void elements as <tag/> rather than <tag>
void_element_close_prefix = ' / '
def substitute_entities ( self , * args , * * kwargs ) :
""" Transform certain characters into named entities. """
raise NotImplementedError ( )
class HTMLFormatter ( Formatter ) :
""" The default HTML formatter. """
def substitute ( self , * args , * * kwargs ) :
return HTMLAwareEntitySubstitution . substitute_html ( * args , * * kwargs )
class MinimalHTMLFormatter ( Formatter ) :
""" A minimal HTML formatter. """
def substitute ( self , * args , * * kwargs ) :
return HTMLAwareEntitySubstitution . substitute_xml ( * args , * * kwargs )
class HTML5Formatter ( HTMLFormatter ) :
""" An HTML formatter that omits the slash in a void tag. """
void_element_close_prefix = None
self . next_element = next_element
if self . next_element is not None :
self . next_element . previous_element = self
class XMLFormatter ( Formatter ) :
""" Substitute only the essential XML entities. """
def substitute ( self , * args , * * kwargs ) :
return EntitySubstitution . substitute_xml ( * args , * * kwargs )
self . next_sibling = next_sibling
if self . next_sibling is not None :
self . next_sibling . previous_sibling = self
class HTMLXMLFormatter ( Formatter ) :
""" Format XML using HTML rules. """
def substitute ( self , * args , * * kwargs ) :
return HTMLAwareEntitySubstitution . substitute_html ( * args , * * kwargs )
if ( previous_sibling is None
and self . parent is not None and self . parent . contents ) :
previous_sibling = self . parent . contents [ - 1 ]
class PageElement ( object ) :
""" Contains the navigational information for some part of the page
( either a tag or a piece of text ) """
self . previous_sibling = previous_sibling
if previous_sibling is not None :
self . previous_sibling . next_sibling = self
# There are five possible values for the "formatter" argument passed in
# to methods like encode() and prettify():
#
# "html" - All Unicode characters with corresponding HTML entities
# are converted to those entities on output.
# "html5" - The same as "html", but empty void tags are represented as
# <tag> rather than <tag/>
# "minimal" - Bare ampersands and angle brackets are converted to
# XML entities: & < >
# None - The null formatter. Unicode characters are never
# converted to entities. This is not recommended, but it's
# faster than "minimal".
# A callable function - it will be called on every string that needs to undergo entity substitution.
# A Formatter instance - Formatter.substitute(string) will be called on every string that
# needs to undergo entity substitution.
#
# In an HTML document, the default "html", "html5", and "minimal"
# functions will leave the contents of <script> and <style> tags
# alone. For an XML document, all tags will be given the same
# treatment.
HTML_FORMATTERS = {
" html " : HTMLFormatter ( ) ,
" html5 " : HTML5Formatter ( ) ,
" minimal " : MinimalHTMLFormatter ( ) ,
None : None
}
XML_FORMATTERS = {
" html " : HTMLXMLFormatter ( ) ,
" minimal " : XMLFormatter ( ) ,
None : None
}
def format_string ( self , s , formatter = ' minimal ' ) :
def format_string ( self , s , formatter ) :
""" Format the given string using the given formatter. """
if isinstance ( formatter , basestring ) :
formatter = self . _formatter_for_name ( formatter )
if formatter is None :
output = s
else :
if isinstance ( formatter , Callable ) :
# Backwards compatibility -- you used to pass in a formatting method.
output = formatter ( s )
else :
output = formatter . substitute ( s )
return s
if not isinstance ( formatter , Formatter ) :
formatter = self . formatter_for_name ( formatter )
output = formatter . substitute ( s )
return output
def formatter_for_name ( self , formatter ) :
""" Look up or create a Formatter for the given identifier,
if necessary .
: param formatter : Can be a Formatter object ( used as - is ) , a
function ( used as the entity substitution hook for an
XMLFormatter or HTMLFormatter ) , or a string ( used to look up
an XMLFormatter or HTMLFormatter in the appropriate registry .
"""
if isinstance ( formatter , Formatter ) :
return formatter
if self . _is_xml :
c = XMLFormatter
else :
c = HTMLFormatter
if callable ( formatter ) :
return c ( entity_substitution = formatter )
return c . REGISTRY [ formatter ]
@property
def _is_xml ( self ) :
""" Is this element part of an XML tree or an HTML tree?
This is used when mapping a formatter name ( " minimal " ) to an
appropriate function ( one that performs entity - substitution on
the contents of < script > and < style > tags , or not ) . It can be
This is used in formatter_for_name , when deciding whether an
XMLFormatter or HTMLFormatter is more appropriate . It can be
inefficient , but it should be called very rarely .
"""
if self . known_xml is not None :
@ -248,46 +190,13 @@ class PageElement(object):
return getattr ( self , ' is_xml ' , False )
return self . parent . _is_xml
def _formatter_for_name ( self , name ) :
" Look up a formatter function based on its name and the tree. "
if self . _is_xml :
return self . XML_FORMATTERS . get ( name , XMLFormatter ( ) )
else :
return self . HTML_FORMATTERS . get ( name , HTMLFormatter ( ) )
def setup ( self , parent = None , previous_element = None , next_element = None ,
previous_sibling = None , next_sibling = None ) :
""" Sets up the initial relations between this element and
other elements . """
self . parent = parent
self . previous_element = previous_element
if previous_element is not None :
self . previous_element . next_element = self
self . next_element = next_element
if self . next_element is not None :
self . next_element . previous_element = self
self . next_sibling = next_sibling
if self . next_sibling is not None :
self . next_sibling . previous_sibling = self
if ( previous_sibling is None
and self . parent is not None and self . parent . contents ) :
previous_sibling = self . parent . contents [ - 1 ]
self . previous_sibling = previous_sibling
if previous_sibling is not None :
self . previous_sibling . next_sibling = self
nextSibling = _alias ( " next_sibling " ) # BS3
previousSibling = _alias ( " previous_sibling " ) # BS3
def replace_with ( self , replace_with ) :
if self . parent is None :
raise ValueError (
" Cannot replace one element with another when the "
" Cannot replace one element with another when the "
" element to be replaced is not part of a tree. " )
if replace_with is self :
return
@ -742,6 +651,7 @@ class NavigableString(unicode, PageElement):
self . __class__ . __name__ , attr ) )
def output_ready ( self , formatter = " minimal " ) :
""" Run the string through the provided formatter. """
output = self . format_string ( self , formatter )
return self . PREFIX + output + self . SUFFIX
@ -760,10 +670,12 @@ class PreformattedString(NavigableString):
but the return value will be ignored .
"""
def output_ready ( self , formatter = " minimal " ) :
""" CData strings are passed into the formatter.
But the return value is ignored . """
self . format_string ( self , formatter )
def output_ready ( self , formatter = None ) :
""" CData strings are passed into the formatter, purely
for any side effects . The return value is ignored .
"""
if formatter is not None :
ignore = self . format_string ( self , formatter )
return self . PREFIX + self + self . SUFFIX
class CData ( PreformattedString ) :
@ -817,7 +729,10 @@ class Tag(PageElement):
def __init__ ( self , parser = None , builder = None , name = None , namespace = None ,
prefix = None , attrs = None , parent = None , previous = None ,
is_xml = None ) :
is_xml = None , sourceline = None , sourcepos = None ,
can_be_empty_element = None , cdata_list_attributes = None ,
preserve_whitespace_tags = None
) :
" Basic constructor. "
if parser is None :
@ -831,14 +746,10 @@ class Tag(PageElement):
self . name = name
self . namespace = namespace
self . prefix = prefix
if builder is not None :
preserve_whitespace_tags = builder . preserve_whitespace_tags
else :
if is_xml :
preserve_whitespace_tags = [ ]
else :
preserve_whitespace_tags = HTMLAwareEntitySubstitution . preserve_whitespace_tags
self . preserve_whitespace_tags = preserve_whitespace_tags
if ( ( not builder or builder . store_line_numbers )
and ( sourceline is not None or sourcepos is not None ) ) :
self . sourceline = sourceline
self . sourcepos = sourcepos
if attrs is None :
attrs = { }
elif attrs :
@ -861,12 +772,33 @@ class Tag(PageElement):
self . setup ( parent , previous )
self . hidden = False
# Set up any substitutions, such as the charset in a META tag.
if builder is not None :
if builder is None :
# In the absence of a TreeBuilder, use whatever values were
# passed in here. They're probably None, unless this is a copy of some
# other tag.
self . can_be_empty_element = can_be_empty_element
self . cdata_list_attributes = cdata_list_attributes
self . preserve_whitespace_tags = preserve_whitespace_tags
else :
# Set up any substitutions for this tag, such as the charset in a META tag.
builder . set_up_substitutions ( self )
# Ask the TreeBuilder whether this tag might be an empty-element tag.
self . can_be_empty_element = builder . can_be_empty_element ( name )
else :
self . can_be_empty_element = False
# Keep track of the list of attributes of this tag that
# might need to be treated as a list.
#
# For performance reasons, we store the whole data structure
# rather than asking the question of every tag. Asking would
# require building a new data structure every time, and
# (unlike can_be_empty_element), we almost never need
# to check this.
self . cdata_list_attributes = builder . cdata_list_attributes
# Keep track of the names that might cause this tag to be treated as a
# whitespace-preserved tag.
self . preserve_whitespace_tags = builder . preserve_whitespace_tags
parserClass = _alias ( " parser_class " ) # BS3
@ -874,8 +806,14 @@ class Tag(PageElement):
""" A copy of a Tag is a new Tag, unconnected to the parse tree.
Its contents are a copy of the old Tag ' s contents.
"""
clone = type ( self ) ( None , self . builder , self . name , self . namespace ,
self . prefix , self . attrs , is_xml = self . _is_xml )
clone = type ( self ) (
None , self . builder , self . name , self . namespace ,
self . prefix , self . attrs , is_xml = self . _is_xml ,
sourceline = self . sourceline , sourcepos = self . sourcepos ,
can_be_empty_element = self . can_be_empty_element ,
cdata_list_attributes = self . cdata_list_attributes ,
preserve_whitespace_tags = self . preserve_whitespace_tags
)
for attr in ( ' can_be_empty_element ' , ' hidden ' ) :
setattr ( clone , attr , getattr ( self , attr ) )
for child in self . contents :
@ -981,6 +919,43 @@ class Tag(PageElement):
for element in self . contents [ : ] :
element . extract ( )
def smooth ( self ) :
""" Smooth out this element ' s children by consolidating consecutive strings.
This makes pretty - printed output look more natural following a
lot of operations that modified the tree .
"""
# Mark the first position of every pair of children that need
# to be consolidated. Do this rather than making a copy of
# self.contents, since in most cases very few strings will be
# affected.
marked = [ ]
for i , a in enumerate ( self . contents ) :
if isinstance ( a , Tag ) :
# Recursively smooth children.
a . smooth ( )
if i == len ( self . contents ) - 1 :
# This is the last item in .contents, and it's not a
# tag. There's no chance it needs any work.
continue
b = self . contents [ i + 1 ]
if ( isinstance ( a , NavigableString )
and isinstance ( b , NavigableString )
and not isinstance ( a , PreformattedString )
and not isinstance ( b , PreformattedString )
) :
marked . append ( i )
# Go over the marked positions in reverse order, so that
# removing items from .contents won't affect the remaining
# positions.
for i in reversed ( marked ) :
a = self . contents [ i ]
b = self . contents [ i + 1 ]
b . extract ( )
n = NavigableString ( a + b )
a . replace_with ( n )
def index ( self , element ) :
"""
Find the index of a child by identity , not value . Avoids issues with
@ -1115,14 +1090,6 @@ class Tag(PageElement):
u = self . decode ( indent_level , encoding , formatter )
return u . encode ( encoding , errors )
def _should_pretty_print ( self , indent_level ) :
""" Should this tag be pretty-printed? """
return (
indent_level is not None
and self . name not in self . preserve_whitespace_tags
)
def decode ( self , indent_level = None ,
eventual_encoding = DEFAULT_OUTPUT_ENCODING ,
formatter = " minimal " ) :
@ -1136,30 +1103,32 @@ class Tag(PageElement):
encoding .
"""
# First off, turn a string formatter into a Formatter object. This
# will stop the lookup from happening over and over again.
if not isinstance ( formatter , Formatter ) and not isinstance ( formatter , Callable ) :
formatter = self . _formatter_for_name ( formatter )
# First off, turn a non-Formatter `formatter` into a Formatter
# object. This will stop the lookup from happening over and
# over again.
if not isinstance ( formatter , Formatter ) :
formatter = self . formatter_for_name ( formatter )
attributes = formatter . attributes ( self )
attrs = [ ]
if self . attrs :
for key , val in sorted ( self . attrs . items ( ) ) :
if val is None :
decoded = key
else :
if isinstance ( val , list ) or isinstance ( val , tuple ) :
val = ' ' . join ( val )
elif not isinstance ( val , basestring ) :
val = unicode ( val )
elif (
for key , val in attributes :
if val is None :
decoded = key
else :
if isinstance ( val , list ) or isinstance ( val , tuple ) :
val = ' ' . join ( val )
elif not isinstance ( val , basestring ) :
val = unicode ( val )
elif (
isinstance ( val , AttributeValueWithCharsetSubstitution )
and eventual_encoding is not None ) :
val = val . encode ( eventual_encoding )
text = self . format_string ( val , formatter )
decoded = (
unicode ( key ) + ' = '
+ EntitySubstitution . quoted_attribute_value ( text ) )
attrs . append ( decoded )
and eventual_encoding is not None
) :
val = val . encode ( eventual_encoding )
text = formatter . attribute_value ( val )
decoded = (
unicode ( key ) + ' = '
+ formatter . quoted_attribute_value ( text ) )
attrs . append ( decoded )
close = ' '
closeTag = ' '
@ -1168,9 +1137,7 @@ class Tag(PageElement):
prefix = self . prefix + " : "
if self . is_empty_element :
close = ' '
if isinstance ( formatter , Formatter ) :
close = formatter . void_element_close_prefix or close
close = formatter . void_element_close_prefix or ' '
else :
closeTag = ' </ %s %s > ' % ( prefix , self . name )
@ -1185,7 +1152,8 @@ class Tag(PageElement):
else :
indent_contents = None
contents = self . decode_contents (
indent_contents , eventual_encoding , formatter )
indent_contents , eventual_encoding , formatter
)
if self . hidden :
# This is the 'document root' object.
@ -1217,6 +1185,16 @@ class Tag(PageElement):
s = ' ' . join ( s )
return s
def _should_pretty_print ( self , indent_level ) :
""" Should this tag be pretty-printed? """
return (
indent_level is not None
and (
not self . preserve_whitespace_tags
or self . name not in self . preserve_whitespace_tags
)
)
def prettify ( self , encoding = None , formatter = " minimal " ) :
if encoding is None :
return self . decode ( True , formatter = formatter )
@ -1232,19 +1210,19 @@ class Tag(PageElement):
indented this many spaces .
: param eventual_encoding : The tag is destined to be
encoded into this encoding . This method is _not_
encoded into this encoding . decode_contents ( ) is _not_
responsible for performing that encoding . This information
is passed in so that it can be substituted in if the
document contains a < META > tag that mentions the document ' s
encoding .
: param formatter : The output formatter responsible for converting
entities to Unicode charac ters.
: param formatter : A Formatter object , or a string naming one of
the standard Format ters .
"""
# First off, turn a string formatter into a Formatter object. This
# will stop the lookup from happening over and over again.
if not isinstance ( formatter , Formatter ) and not isinstance ( formatter , Callable ) :
formatter = self . _ formatter_for_name( formatter )
if not isinstance ( formatter , Formatter ) :
formatter = self . formatter_for_name ( formatter )
pretty_print = ( indent_level is not None )
s = [ ]
@ -1255,16 +1233,19 @@ class Tag(PageElement):
elif isinstance ( c , Tag ) :
s . append ( c . decode ( indent_level , eventual_encoding ,
formatter ) )
if text and indent_level and not self . name == ' pre ' :
preserve_whitespace = (
self . preserve_whitespace_tags and self . name in self . preserve_whitespace_tags
)
if text and indent_level and not preserve_whitespace :
text = text . strip ( )
if text :
if pretty_print and not self . name == ' pre ' :
if pretty_print and not preserve_whitespace :
s . append ( " " * ( indent_level - 1 ) )
s . append ( text )
if pretty_print and not self . name == ' pre ' :
if pretty_print and not preserve_whitespace :
s . append ( " \n " )
return ' ' . join ( s )
def encode_contents (
self , indent_level = None , encoding = DEFAULT_OUTPUT_ENCODING ,
formatter = " minimal " ) :
JackDandy
6 years ago