从网站上获取一些波高,当波高达到两位数范围时,我的代码就失败了。在
例如:目前代码将从站点中分别从“1”和“2”中提取12,而不是“12”。在
#Author: David Owens
#File name: soupScraper.py
#Description: html scraper that takes surf reports from various websites
import csv
import requests
from bs4 import BeautifulSoup
NUM_SITES = 2
reportsFinal = []
###################### SURFLINE URL STRINGS AND TAG ###########################
slRootUrl = 'http://www.surfline.com/surf-report/'
slSunsetCliffs = 'sunset-cliffs-southern-california_4254/'
slScrippsUrl = 'scripps-southern-california_4246/'
slBlacksUrl = 'blacks-southern-california_4245/'
slCardiffUrl = 'cardiff-southern-california_4786/'
slTagText = 'observed-wave-range'
slTag = 'id'
#list of surfline URL endings
slUrls = [slSunsetCliffs, slScrippsUrl, slBlacksUrl]
###############################################################################
#################### MAGICSEAWEED URL STRINGS AND TAG #########################
msRootUrl = 'http://magicseaweed.com/'
msSunsetCliffs = 'Sunset-Cliffs-Surf-Report/4211/'
msScrippsUrl = 'Scripps-Pier-La-Jolla-Surf-Report/296/'
msBlacksUrl = 'Torrey-Pines-Blacks-Beach-Surf-Report/295/'
msTagText = 'rating-text'
msTag = 'li'
#list of magicseaweed URL endings
msUrls = [msSunsetCliffs, msScrippsUrl, msBlacksUrl]
###############################################################################
'''
This class represents a surf break. It contains all wave, wind, & tide data
associated with that break relevant to the website
'''
class surfBreak:
def __init__(self, name,low, high, wind, tide):
self.name = name
self.low = low
self.high = high
self.wind = wind
self.tide = tide
#toString method
def __str__(self):
return '{0}: Wave height: {1}-{2} Wind: {3} Tide: {4}'.format(self.name,
self.low, self.high, self.wind, self.tide)
#END CLASS
'''
This returns the proper attribute from the surf report sites
'''
def reportTagFilter(tag):
return (tag.has_attr('class') and 'rating-text' in tag['class']) \
or (tag.has_attr('id') and tag['id'] == 'observed-wave-range')
#END METHOD
'''
This method checks if the parameter is of type int
'''
def representsInt(s):
try:
int(s)
return True
except ValueError:
return False
#END METHOD
'''
This method extracts all ints from a list of reports
reports: The list of surf reports from a single website
returns: reportNums - A list of ints of the wave heights
'''
def extractInts(reports):
print reports
reportNums = []
afterDash = False
num = 0
tens = 0
ones = 0
#extract all ints from the reports and ditch the rest
for report in reports:
for char in report:
if representsInt(char) == True:
num = int(char)
reportNums.append(num)
else:
afterDash = True
return reportNums
#END METHOD
'''
This method iterates through a list of urls and extracts the surf report from
the webpage dependent upon its tag location
rootUrl: The root url of each surf website
urlList: A list of specific urls to be appended to the root url for each
break
tag: the html tag where the actual report lives on the page
returns: a list of strings of each breaks surf report
'''
def extractReports(rootUrl, urlList, tag, tagText):
#empty list to hold reports
reports = []
reportNums = []
index = 0
#loop thru URLs
for url in urlList:
try:
index += 1
#request page
request = requests.get(rootUrl + url)
#turn into soup
soup = BeautifulSoup(request.content, 'lxml')
#get the tag where surflines report lives
reportTag = soup.findAll(reportTagFilter)[0]
reports.append(reportTag.text.strip())
#notify if fail
except:
print 'scrape failure at URL ', index
pass
reportNums = extractInts(reports)
return reportNums
#END METHOD
'''
This method calculates the average of the wave heights
'''
def calcAverages(reportList):
#empty list to hold averages
finalAverages = []
listIndex = 0
waveIndex = 0
#loop thru list of reports to calc each breaks ave low and high
for x in range(0, 6):
#get low ave
average = (reportList[listIndex][waveIndex]
+ reportList[listIndex+1][waveIndex]) / NUM_SITES
finalAverages.append(average)
waveIndex += 1
return finalAverages
#END METHOD
slReports = extractReports(slRootUrl, slUrls, slTag, slTagText)
msReports = extractReports(msRootUrl, msUrls, msTag, msTagText)
reportsFinal.append(slReports)
reportsFinal.append(msReports)
print 'Surfline: ', slReports
print 'Magicseaweed: ', msReports
实际上并不是提取整数,而是浮点,因为
reports
中的值类似于['0.3-0.6 m']
。现在你只需要遍历每个字符,然后一个一个地将它们转换成int,或者丢弃。所以难怪你只能得到个位数。在可以说,从regexp中提取数字的方法很简单:
这个表达式将匹配您的float并将它们作为一个列表返回。在
具体地说,表达式将匹配任何在
'.'
之前和之后至少有一个数字、在它之间有一个'-'
、另一个浮点序列并以'm'
或' m'
结尾的任何内容。然后它将表示浮点数的部分分组到一个元组中。例如,['12.0m-3.0m']
将返回[12.0, 3.0]
。如果您希望它在浮点后面有更多的数字,可以在表达式中的第二个'd'
:s之后添加一个额外的'+'
。在相关问题 更多 >
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