Python网络编程 获取页面中的天气信息
Python 网络编程基础，由于原书用的测试网站数据改变，无法正常获取天气信息。
#!/usr/bin/env python
# -*- coding:gb2312 -*-
from htmlentitydefs import entitydefs
from HTMLParser import HTMLParser
import sys, re, urllib2
#define a list of interesting tables.
interesting = ['Day Forecast for ZIP']
#定义一个HTMLParser.HTMLParser子类，并添加用来处理不同标签的函数
class WeatherParser(HTMLParser):
"""Class to parse weather data from www.wunderground.com."""
def __init__(self):
# Storage for parse tree
self.taglevels = []
# List of tags that are interesting
self.handledtags = ['title', 'table', 'tr', 'td', 'th']
# Set to the interesting tag currently being processed
self.processing = None
# True if currently processing an interesting tables
self.interestingtable = 0
# If processing an interesting table, holds cells in current row
self.row = []
# Initialize base class
HTMLParser.__init__(self)
def handle_starttag(self, tag, attrs):
"""Called by base class to handle start tags. whenever a start tag is encountered."""
if len(self.taglevels) and self.taglevels[-1]==tag:
#Processing a previous version of this tag. Close it out
#and then start a new on this one.
self.handle_endtag(tag)
#Note that we're now processing this tag，只要是一个开始标签就添加
self.taglevels.append(tag)
if tag == 'br':
# Add a special newline token to the stream
self.handle_data("<NEWLINE>")
#如果是一个我们要处理的标签
elif tag in self.handledtags:
#Only bother saving off the data if it's a tag we handle.
self.data = ''
self.processing = tag
def handle_data(self, data):
""" Called by both HTMLParser and methods in WeatherParser to handle plain data. This function simply records incoming data if we are presently inside a handled tag."""
if self.processing: #检查是否处理这个标签，如果是就记录其中的数据
#通常这是一个慢又差的方法
self.data += data
def handle_endtag(self, tag):
"""Handle a closing tag."""
if not tag in self.taglevels:
#we didn't have a start tag for this anyway. Just ignore.
return
while len(self.taglevels):
#get the last tag on the list and remove it
starttag = self.taglevels.pop()
#finish processing it.
if starttag in self.handledtags:
self.finishprocessing(starttag)
#if it's our tag, stop now
if starttag == tag:
break
def cleanse(self):
"""Remove extra whitespace from the document."""
# \xa0 is the non-breaking space( in HTML)
self.data = re.sub('(\s|\xa0)+',' ',self.data)
self.data = self.data.replace('<NEWLINE>',"\n").strip()
def finishprocessing(self, tag):
""" Called by handle_endtag() to handle an interesting end tag."""
global interesting
self.cleanse()
if tag == 'title' and tag == self.processing:
#print out the title of page
print "*** %s ***" % self.data
elif (tag == 'td' or tag == 'th') and tag == self.processing:
# Got a cell in a table.
if not self.interestingtable:
# If we're not already in an interesting table, see if this cell makes the table interesting.
for item in interesting:
if re.search(item, self.data, re.I):
#yep, found an interestingtable. Note that, then remove it from the interesting list, print out a heading, and stop looking at the list.
self.interestingtable = 1
interesting = [x for x in interesting if x!= item]
print "\n *** %s\n" % self.data.strip()
break
else:
# Already in an interestingtable; just add this cell to the curren row.
self.row.append(self.data)
elif tag == 'tr' and self.interestingtable:
# print out an interesting row.
self.writerow()
self.row = []
elif tag == 'table':
#End of a table: note that system is no longer processing an interestingtable.
self.interestingtable = 0
self.processing = None
def writerow(self):
"""Format a row for on-screen display."""
cells = len(self.row)
if cells < 2:
#if there are no cells, the row is empty; display nothing.
#if there is 1 cell, wunderground.com uses it as a header.
#we don't want it, so again, display noting.
return
if cells > 2:
#if it's a table with lots of cells, give each cell
#the same amount of space, leaving room for a space between cells.
width = (78 - cells) / cells
maxwidth = width
else:
#if it's a table with two cells, make the left one narrow
#and the rightone wide.\
width = 20
maxwidth = 58
# Continue looping while at least one cell has a line of data to print
while [x for x in self.row if x!='']:
#process each cell in the row.
for i in range(len(self.row)):
thisline = self.row[i]
if thisline.find("\n")!=-1:
#if it has multiple lines, we want only the first;
# save it in thisline, and shove the rest back into
# the list for processing later.
(thisline, self.row[i]) = self.row[i].split("\n",1)
else:
#just one line, we've already got it in thisline,
#so put the empty string in the list for later.
self.row[i] = ''
thisline = thisline.strip()
sys.stdout.write("%-*.*s " % (width, maxwidth, thisline))
sys.stdout.write("\n")
#处理html中的实体方法
def handle_entityref(self, name):
if entitydefs.has_key(name):
self.handle_data(entitydefs[name])
else:
self.handle_data('&' + name + ';')
#convert the character reference like ®商标符号
def handle_charref(self, name):
#Validate the name.
try:
charnum = int(name)
except ValueError:
return
if charnum < 1 or charnum > 255:
return
self.handle_data(chr(charnum))
#HTMLParser的feed()方法会适当地调用handle_starttag,handle_data,handle_endtag方法。
sys.stdout.write("Enter ZIP code: ")
zip = sys.stdin.readline().strip()
url="http://www.wunderground.com/cgi-bin/findweather/getForecast?query="+zip+"&wuSelect=WEATHER"
print url
req = urllib2.Request(url)
fd = urllib2.urlopen(req)
#用正则表达式处理HTML中不规范的代码，在把文档发给HTMLParser之前，要预处理
parser = WeatherParser()
data = fd.read()
data = re.sub(' ([^ =]+)=[^ ="]+="', ' \\1="', data)
data = re.sub('(?s)<!--.*?-->','', data)
parser.feed(data)
#!/usr/bin/env python
# -*- coding:gb2312 -*-
from htmlentitydefs import entitydefs
from HTMLParser import HTMLParser
import sys, re, urllib2
#define a list of interesting tables.
interesting = ['Day Forecast for ZIP']
#定义一个HTMLParser.HTMLParser子类，并添加用来处理不同标签的函数
class WeatherParser(HTMLParser):
"""Class to parse weather data from www.wunderground.com."""
def __init__(self):
# Storage for parse tree
self.taglevels = []
# List of tags that are interesting
self.handledtags = ['title', 'table', 'tr', 'td', 'th']
# Set to the interesting tag currently being processed
self.processing = None
# True if currently processing an interesting tables
self.interestingtable = 0
# If processing an interesting table, holds cells in current row
self.row = []
# Initialize base class
HTMLParser.__init__(self)
def handle_starttag(self, tag, attrs):
"""Called by base class to handle start tags. whenever a start tag is encountered."""
if len(self.taglevels) and self.taglevels[-1]==tag:
#Processing a previous version of this tag. Close it out
#and then start a new on this one.
self.handle_endtag(tag)
#Note that we're now processing this tag，只要是一个开始标签就添加
self.taglevels.append(tag)
if tag == 'br':
# Add a special newline token to the stream
self.handle_data("<NEWLINE>")
#如果是一个我们要处理的标签
elif tag in self.handledtags:
#Only bother saving off the data if it's a tag we handle.
self.data = ''
self.processing = tag
def handle_data(self, data):
""" Called by both HTMLParser and methods in WeatherParser to handle plain data. This function simply records incoming data if we are presently inside a handled tag."""
if self.processing: #检查是否处理这个标签，如果是就记录其中的数据
#通常这是一个慢又差的方法
self.data += data
def handle_endtag(self, tag):
"""Handle a closing tag."""
if not tag in self.taglevels:
#we didn't have a start tag for this anyway. Just ignore.
return
while len(self.taglevels):
#get the last tag on the list and remove it
starttag = self.taglevels.pop()
#finish processing it.
if starttag in self.handledtags:
self.finishprocessing(starttag)
#if it's our tag, stop now
if starttag == tag:
break
def cleanse(self):
"""Remove extra whitespace from the document."""
# \xa0 is the non-breaking space( in HTML)
self.data = re.sub('(\s|\xa0)+',' ',self.data)
self.data = self.data.replace('<NEWLINE>',"\n").strip()
def finishprocessing(self, tag):
""" Called by handle_endtag() to handle an interesting end tag."""
global interesting
self.cleanse()
if tag == 'title' and tag == self.processing:
#print out the title of page
print "*** %s ***" % self.data
elif (tag == 'td' or tag == 'th') and tag == self.processing:
# Got a cell in a table.
if not self.interestingtable:
# If we're not already in an interesting table, see if this cell makes the table interesting.
for item in interesting:
if re.search(item, self.data, re.I):
#yep, found an interestingtable. Note that, then remove it from the interesting list, print out a heading, and stop looking at the list.
self.interestingtable = 1
interesting = [x for x in interesting if x!= item]
print "\n *** %s\n" % self.data.strip()
break
else:
# Already in an interestingtable; just add this cell to the curren row.
self.row.append(self.data)
elif tag == 'tr' and self.interestingtable:
# print out an interesting row.
self.writerow()
self.row = []
elif tag == 'table':
#End of a table: note that system is no longer processing an interestingtable.
self.interestingtable = 0
self.processing = None
def writerow(self):
"""Format a row for on-screen display."""
cells = len(self.row)
if cells < 2:
#if there are no cells, the row is empty; display nothing.
#if there is 1 cell, wunderground.com uses it as a header.
#we don't want it, so again, display noting.
return
if cells > 2:
#if it's a table with lots of cells, give each cell
#the same amount of space, leaving room for a space between cells.
width = (78 - cells) / cells
maxwidth = width
else:
#if it's a table with two cells, make the left one narrow
#and the rightone wide.\
width = 20
maxwidth = 58
# Continue looping while at least one cell has a line of data to print
while [x for x in self.row if x!='']:
#process each cell in the row.
for i in range(len(self.row)):
thisline = self.row[i]
if thisline.find("\n")!=-1:
#if it has multiple lines, we want only the first;
# save it in thisline, and shove the rest back into
# the list for processing later.
(thisline, self.row[i]) = self.row[i].split("\n",1)
else:
#just one line, we've already got it in thisline,
#so put the empty string in the list for later.
self.row[i] = ''
thisline = thisline.strip()
sys.stdout.write("%-*.*s " % (width, maxwidth, thisline))
sys.stdout.write("\n")
#处理html中的实体方法
def handle_entityref(self, name):
if entitydefs.has_key(name):
self.handle_data(entitydefs[name])
else:
self.handle_data('&' + name + ';')
#convert the character reference like ®商标符号
def handle_charref(self, name):
#Validate the name.
try:
charnum = int(name)
except ValueError:
return
if charnum < 1 or charnum > 255:
return
self.handle_data(chr(charnum))
#HTMLParser的feed()方法会适当地调用handle_starttag,handle_data,handle_endtag方法。
sys.stdout.write("Enter ZIP code: ")
zip = sys.stdin.readline().strip()
url="http://www.wunderground.com/cgi-bin/findweather/getForecast?query="+zip+"&wuSelect=WEATHER"
print url
req = urllib2.Request(url)
fd = urllib2.urlopen(req)
#用正则表达式处理HTML中不规范的代码，在把文档发给HTMLParser之前，要预处理
parser = WeatherParser()
data = fd.read()
data = re.sub(' ([^ =]+)=[^ ="]+="', ' \\1="', data)
data = re.sub('(?s)<!--.*?-->','', data)
parser.feed(data)
