要求
将以下文档作为网页模版，编程实现由用户定义网页信息并将网页输出保存<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" \
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
<head>
<title>{title}</title>
<!-- {copyright} -->
<meta name="Description" content="{description}" />
<meta name="Keywords" content="{keywords}" />
<meta equiv="content-type" content="text/html; charset=utf-8" />
{stylesheet}\
</head>
<body>
</body>
</html>
源码
import datetime
import xml.sax.saxutils
COPYRIGHT_TEMPLATE = "Copyright (c) {0} {1}. All rights reserved."
STYLESHEET_TEMPLATE = ('<link rel="stylesheet" type="text/css" '
'media="all" href="{0}" />\n')
HTML_TEMPLATE = """<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" \
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
<head>
<title>{title}</title>
<!-- {copyright} -->
<meta name="Description" content="{description}" />
<meta name="Keywords" content="{keywords}" />
<meta equiv="content-type" content="text/html; charset=utf-8" />
{stylesheet}\
</head>
<body>
</body>
</html>
"""
class CancelledError(Exception): pass #自定义异常
def main():
information = dict(name=None, year=datetime.date.today().year,
filename=None, title=None, description=None,
keywords=None, stylesheet=None)
while True:
try:
print("\nMake HTML Skeleton\n")
populate_information(information) #注意两种参数用法的异同
make_html_skeleton(**information) #注意两种参数用法的异同
except CancelledError:
print("Cancelled")
if (get_string("\nCreate another (y/n)?", default="y").lower()
not in {"y", "yes"}):
break
def populate_information(information):
name = get_string("Enter your name (for copyright)", "name",
information["name"])
if not name:
raise CancelledError()
year = get_integer("Enter copyright year", "year",
information["year"], 2000,
datetime.date.today().year + 1, True)
if year == 0:
raise CancelledError() #弹出异常
filename = get_string("Enter filename", "filename")
if not filename:
raise CancelledError()
if not filename.endswith((".htm", ".html")):
filename += ".html"
title = get_string("Enter title", "title")
if not title:
raise CancelledError()
description = get_string("Enter description (optional)",
"description")
keywords = []
while True:
keyword = get_string("Enter a keyword (optional)", "keyword")
if keyword:
keywords.append(keyword)
else:
break
stylesheet = get_string("Enter the stylesheet filename "
"(optional)", "stylesheet")
if stylesheet and not stylesheet.endswith(".css"):
stylesheet += ".css"
information.update(name=name, year=year, filename=filename,
title=title, description=description,
keywords=keywords, stylesheet=stylesheet)
def make_html_skeleton(year, name, title, description, keywords,
stylesheet, filename):
copyright = COPYRIGHT_TEMPLATE.format(year,
xml.sax.saxutils.escape(name))
#xmlsax.saxutils.escape()函数，接受一个字符串，并返回一个带有html字符的字符串（"&"、"<"、">"分别以转义符"&"、"<"、"$gt;"的形式出现）
title = xml.sax.saxutils.escape(title)
description = xml.sax.saxutils.escape(description)
keywords = ",".join([xml.sax.saxutils.escape(k) #将排列变成字符串，并用逗号隔开
for k in keywords]) if keywords else ""
stylesheet = (STYLESHEET_TEMPLATE.format(stylesheet)
if stylesheet else "")
html = HTML_TEMPLATE.format(**locals())
fh = None
try:
fh = open(filename, "w", encoding="utf8")
fh.write(html)
except EnvironmentError as err:
print("ERROR", err)
else:
print("Saved skeleton", filename)
finally:
if fh is not None:
fh.close()
def get_string(message, name="string", default=None,
minimum_length=0, maximum_length=80):
message += ": " if default is None else " [{0}]: ".format(default)
while True:
try:
line = input(message)
if not line:
if default is not None:
return default
if minimum_length == 0:
return ""
else:
raise ValueError("{0} may not be empty".format(
name))
if not (minimum_length <= len(line) <= maximum_length):
raise ValueError("{name} must have at least "
"{minimum_length} and at most "
"{maximum_length} characters".format(
**locals()))
return line
except ValueError as err:
print("ERROR", err)
def get_integer(message, name="integer", default=None, minimum=0,
maximum=100, allow_zero=True):
class RangeError(Exception): pass
message += ": " if default is None else " [{0}]: ".format(default)
while True:
try:
line = input(message)
if not line and default is not None:
return default
i = int(line)
if i == 0:
if allow_zero:
return i
else:
raise RangeError("{0} may not be 0".format(name))
if not (minimum <= i <= maximum):
raise RangeError("{name} must be between {minimum} "
"and {maximum} inclusive{0}".format(
" (or 0)" if allow_zero else "", **locals()))
return i
except RangeError as err:
print("ERROR", err)
except ValueError as err:
print("ERROR {0} must be an integer".format(name))
main()
出现的问题与用的的知识点
Python菜鸟晋级08----str.format()方法欢迎收听我的微信公众号
