P21039 [HackerRank] Html parser part 1
普及-
题目描述

HTML

Hypertext Markup Language is a standard markup language used for creating World Wide Web pages.

Parsing

Parsing is the process of syntactic analysis of a string of symbols. It involves resolving a string into its component parts and describing their syntactic roles.

HTMLParser

An HTMLParser instance is fed HTML data and calls handler methods when start tags, end tags, text, comments, and other markup elements are encountered.

Example (based on the original Python documentation):

_{Code}

from HTMLParser import HTMLParser

create a subclass and override the handler methods

class MyHTMLParser(HTMLParser):
def handle_starttag(self, tag, attrs):
print "Found a start tag :", tag
def handle_endtag(self, tag):
print "Found an end tag :", tag
def handle_startendtag(self, tag, attrs):
print "Found an empty tag :", tag

instantiate the parser and fed it some HTML

parser = MyHTMLParser()
parser.feed("<html><head><title>HTML Parser - I</title></head>"
+"<body>

HackerRank


</body></html>")

Output

Found a start tag : html
Found a start tag : head
Found a start tag : title
Found an end tag : title
Found an end tag : head
Found a start tag : body
Found a start tag : h1
Found an end tag : h1
Found an empty tag : br
Found an end tag : body
Found an end tag : html

.handle_starttag(tag, attrs)

This method is called to handle the start tag of an element. (For example:

)

The tag argument is the name of the tag converted to lowercase.

The attrs argument is a list of (name, value) pairs containing the attributes found inside the tag’s <> brackets.

.handle_endtag(tag)

This method is called to handle the end tag of an element. (For example:

)

The tag argument is the name of the tag converted to lowercase.

.handle_startendtag(tag,attrs)

This method is called to handle the empty tag of an element. (For example:
)

The tag argument is the name of the tag converted to lowercase.

The attrs argument is a list of (name, value) pairs containing the attributes found inside the tag’s <> brackets.

Task

You are given an HTML code snippet of $N$ lines.

Your task is to print start tags, end tags and empty tags separately.

Format your results in the following way:

Start : Tag1
End : Tag1
Start : Tag2
-> Attribute2[0] > Attribute_value2[0]
-> Attribute2[1] > Attribute_value2[1]
-> Attribute2[2] > Attribute_value2[2]
Start : Tag3
-> Attribute3[0] > None
Empty : Tag4
-> Attribute4[0] > Attribute_value4[0]
End : Tag3
End : Tag2

Here, the -> symbol indicates that the tag contains an attribute. It is immediately followed by the name of the attribute and the attribute value.

The > symbol acts as a separator of the attribute and the attribute value.

If an HTML tag has no attribute then simply print the name of the tag.

If an attribute has no attribute value then simply print the name of the attribute value as None.

Note: Do not detect any HTML tag, attribute or attribute value inside the HTML comment tags ().Comments can be multiline as well.

Input Format

The first line contains integer $N$, the number of lines in a HTML code snippet.

The next $N$ lines contain HTML code.

Constraints

$0<N<100$

Output Format

Print the HTML tags, attributes and attribute values in order of their occurrence from top to bottom in the given snippet.

Use proper formatting as explained in the problem statement.

Sample Input
2

<html><head><title>HTML Parser - I</title></head> <body data-modal-target class='1'>

HackerRank


</body></html>

Sample Output
Start : html
Start : head
Start : title
End : title
End : head
Start : body
-> data-modal-target > None
-> class > 1
Start : h1
End : h1
Empty : br
End : body
End : html

输入格式

见题面

输出格式

见题面

样例输入
2 <html><head><title>HTML Parser - I</title></head> <body data-modal-target class='1'><h1>HackerRank</h1><br /></body></html>
样例输出
Start : html Start : head Start : title End : title End : head Start : body -> data-modal-target > None -> class > 1 Start : h1 End : h1 Empty : br End : body End : html