diff --git a/demo1.py b/demo1.py
index 018f33e..82ebe9d 100644
--- a/demo1.py
+++ b/demo1.py
@@ -1,4 +1,5 @@
 from lxml import etree
+
 text = '''
 <div>
     <ul>
@@ -12,4 +13,4 @@
 '''
 html = etree.HTML(text)
 result = etree.tostring(html)
-print(result.decode('utf-8'))
\ No newline at end of file
+print(result.decode('utf-8'))
diff --git a/demo10.py b/demo10.py
index 1471412..6f6fa3e 100644
--- a/demo10.py
+++ b/demo10.py
@@ -2,4 +2,4 @@
 
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//li[@class="item-0"]/text()')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo11.py b/demo11.py
index 5b42109..28e9b89 100644
--- a/demo11.py
+++ b/demo11.py
@@ -1,4 +1,5 @@
 from lxml import etree
+
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//li[@class="item-0"]/a/text()')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo12.py b/demo12.py
index 5f5a2a0..f99b761 100644
--- a/demo12.py
+++ b/demo12.py
@@ -2,4 +2,4 @@
 
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//li[@class="item-0"]//text()')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo13.py b/demo13.py
index f19fbd4..9ab8bcb 100644
--- a/demo13.py
+++ b/demo13.py
@@ -2,4 +2,4 @@
 
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//li/a/@href')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo14.py b/demo14.py
index ed35846..8ce38fd 100644
--- a/demo14.py
+++ b/demo14.py
@@ -4,4 +4,4 @@
 '''
 html = etree.HTML(text)
 result = html.xpath('//li[@class="li"]/a/text()')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo15.py b/demo15.py
index 97ed58c..7c70449 100644
--- a/demo15.py
+++ b/demo15.py
@@ -1,7 +1,8 @@
 from lxml import etree
+
 text = '''
 <li class="li li-first"><a href="link.html">first item</a></li>
 '''
 html = etree.HTML(text)
 result = html.xpath('//li[contains(@class, "li")]/a/text()')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo16.py b/demo16.py
index e08b1cc..9442d3e 100644
--- a/demo16.py
+++ b/demo16.py
@@ -1,7 +1,8 @@
 from lxml import etree
+
 text = '''
 <li class="li li-first" name="item"><a href="link.html">first item</a></li>
 '''
 html = etree.HTML(text)
 result = html.xpath('//li[contains(@class, "li") and @name="item"]/a/text()')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo17.py b/demo17.py
index 34747da..e0c8e37 100644
--- a/demo17.py
+++ b/demo17.py
@@ -19,4 +19,4 @@
 result = html.xpath('//li[position()<3]/a/text()')
 print(result)
 result = html.xpath('//li[last()-2]/a/text()')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo18.py b/demo18.py
index 7edb665..eefaced 100644
--- a/demo18.py
+++ b/demo18.py
@@ -25,4 +25,4 @@
 result = html.xpath('//li[1]/following::*[2]')
 print(result)
 result = html.xpath('//li[1]/following-sibling::*')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo2.py b/demo2.py
index ee86852..44af2cf 100644
--- a/demo2.py
+++ b/demo2.py
@@ -2,4 +2,4 @@
 
 html = etree.parse('./test.html', etree.HTMLParser())
 result = etree.tostring(html)
-print(result.decode('utf-8'))
\ No newline at end of file
+print(result.decode('utf-8'))
diff --git a/demo3.py b/demo3.py
index 731146e..d69acd0 100644
--- a/demo3.py
+++ b/demo3.py
@@ -1,4 +1,5 @@
 from lxml import etree
+
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//*')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo4.py b/demo4.py
index dbf9377..48bfd7e 100644
--- a/demo4.py
+++ b/demo4.py
@@ -1,5 +1,7 @@
 from lxml import etree
 
 html = etree.parse('./test.html', etree.HTMLParser())
-result = html.xpath('//li/a')
-print(result)
\ No newline at end of file
+# result = html.xpath('//li/a')
+result = html.xpath('//li')
+print(result)
+print(result[0])
diff --git a/demo5.py b/demo5.py
index 091a717..9827817 100644
--- a/demo5.py
+++ b/demo5.py
@@ -2,4 +2,5 @@
 
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//ul//a')
-print(result)
\ No newline at end of file
+print(result)
+print(result[0])
diff --git a/demo6.py b/demo6.py
index a71e5d9..1d58448 100644
--- a/demo6.py
+++ b/demo6.py
@@ -2,4 +2,6 @@
 
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//ul/a')
-print(result)
\ No newline at end of file
+print(result)
+if len(result) != 0:
+    print(result[0])
diff --git a/demo7.py b/demo7.py
index 25911b6..c59605a 100644
--- a/demo7.py
+++ b/demo7.py
@@ -2,4 +2,6 @@
 
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//a[@href="link4.html"]/../@class')
-print(result)
\ No newline at end of file
+print(result)
+if len(result) != 0:
+    print(result[0])
diff --git a/demo8.py b/demo8.py
index 1262b56..a2a61bb 100644
--- a/demo8.py
+++ b/demo8.py
@@ -1,4 +1,5 @@
 from lxml import etree
+
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//a[@href="link4.html"]/parent::*/@class')
-print(result)
\ No newline at end of file
+print(result)
diff --git a/demo9.py b/demo9.py
index 8b03cbe..c75fbc8 100644
--- a/demo9.py
+++ b/demo9.py
@@ -1,4 +1,5 @@
 from lxml import etree
+
 html = etree.parse('./test.html', etree.HTMLParser())
 result = html.xpath('//li[@class="item-0"]')
-print(result)
\ No newline at end of file
+print(result)