diff options
Diffstat (limited to 'bs4/element.py')
| -rw-r--r-- | bs4/element.py | 74 |
1 files changed, 43 insertions, 31 deletions
diff --git a/bs4/element.py b/bs4/element.py index 9d7b3c5..75a76bb 100644 --- a/bs4/element.py +++ b/bs4/element.py @@ -618,27 +618,26 @@ class PageElement(object): _selectors_that_consume_an_extra_token = ['>', '+', '~'] - debug = True + _select_debug = False def select(self, selector, _candidate_generator=None): """Perform a CSS selection operation on the current element.""" - debug = True tokens = selector.split() current_context = [self] if tokens[-1] in self._selectors_that_consume_an_extra_token: raise ValueError( 'Final selector "%s" is missing an argument.' % tokens[-1]) - if self.debug: + if self._select_debug: print 'Running CSS selector "%s"' % selector for index, token in enumerate(tokens): - if self.debug: + if self._select_debug: print ' Considering token "%s"' % token recursive_candidate_generator = None tag_name = None if tokens[index-1] in self._selectors_that_consume_an_extra_token: # This token was consumed by the previous selector. Skip it. - if self.debug: + if self._select_debug: print ' Token was consumed by the previous selector.' continue # Each operation corresponds to a checker function, a rule @@ -687,13 +686,17 @@ class PageElement(object): if pseudo_value < 1: raise ValueError( 'nth-of-type pseudoselector value must be at least 1.') - count = 0 - def nth_child_of_type(tag): - count += 1 - if count == pseudo_value: - return True - return False - checker = nth_child_of_type + class Counter(object): + def __init__(self, destination): + self.count = 0 + self.destination = destination + + def nth_child_of_type(self, tag): + self.count += 1 + if self.count == self.destination: + return True + return False + checker = Counter(pseudo_value).nth_child_of_type else: raise NotImplementedError( 'The following pseudoselectors are implemented: nth-of-type.') @@ -725,57 +728,66 @@ class PageElement(object): # the selector is "foo". next_token = tokens[index+1] def recursive_select(tag): - if self.debug: + if self._select_debug: print ' Calling select("%s") recursively on %s %s' % (next_token, tag.name, tag.attrs) print '-' * 40 for i in tag.select(next_token, recursive_candidate_generator): - print '(Recursive select picked up candidate %s %s)' % (i.name, i.attrs) + if self._select_debug: + print '(Recursive select picked up candidate %s %s)' % (i.name, i.attrs) yield i - if self.debug: + if self._select_debug: print '-' * 40 _use_candidate_generator = recursive_select elif _candidate_generator is None: # By default, a tag's candidates are all of its # children. If tag_name is defined, only yield tags # with that name. - if self.debug: + if self._select_debug: if tag_name: check = "[any]" else: check = tag_name print ' Default candidate generator, tag name="%s"' % check - def default_candidate_generator(tag): - for child in tag.descendants: - if not isinstance(child, Tag): - continue - if tag_name and not child.name == tag_name: - continue - yield child - _use_candidate_generator = default_candidate_generator + if self._select_debug: + # This is redundant with later code, but it stops + # a bunch of bogus tags from cluttering up the + # debug log. + def default_candidate_generator(tag): + for child in tag.descendants: + if not isinstance(child, Tag): + continue + if tag_name and not child.name == tag_name: + continue + yield child + _use_candidate_generator = default_candidate_generator + else: + _use_candidate_generator = lambda x: x.descendants else: _use_candidate_generator = _candidate_generator - if checker is None: - if tag_name: - checker = lambda tag: tag.name == tag_name - new_context = [] for tag in current_context: - if self.debug: + if self._select_debug: print " Running candidate generator on %s %s" % ( tag.name, repr(tag.attrs)) for candidate in _use_candidate_generator(tag): if not isinstance(candidate, Tag): continue + if tag_name and candidate.name != tag_name: + continue if checker is None or checker(candidate): - if self.debug: + if self._select_debug: print " SUCCESS %s %s" % (candidate.name, repr(candidate.attrs)) new_context.append(candidate) - elif self.debug: + elif self._select_debug: print " FAILURE %s %s" % (candidate.name, repr(candidate.attrs)) current_context = new_context + if self._select_debug: + print "Final verdict:" + for i in current_context: + print " %s %s" % (i.name, i.attrs) return current_context # Old non-property versions of the generators, for backwards |