python - Multithreaded screen scraping help needed -

-

i'm relatively new python, , i'm working through screen- scraping application gathers data multiple financial sites. have 4 procedures now. 2 run in couple minutes, , other two... hours each. these 2 information on particular stock symbols have in csv file. there 4,000+ symbols i'm using. know enough know vast majority of time spent in io on wire. it's essential these down 1/2 hour each (or, better. ambitious?) of practical use me. i'm using python 3 , beautifulsoup.

i have general structure of i'm doing below. i've abbreviated conceptually non essential sections. i'm reading many threads on multiple calls/ threads @ once speed things up, , seems there lot of options. can point me in right direction should pursue, based on structure of have far? it'd huge help. i'm sure it's obvious, procedure gets called along other data download procs in main driver module. in advance...

from bs4 import beautifulsoup import misc modules  class stockoption:     def __init__(self, datedownloaded, optiondata):         self.datedownloaded = datedownloaded         self.optiondata = optiondata      def forcsv(self):         return [self.datedownloaded, self.optiondata]  def extract_options(tablerowsfrombeautifulsoup):     optionslist = []     opt in range(0, len(tablerowsfrombeautifulsoup))         optionslist.append(stockoption(data parsed tablerows arg))     return optionslist  def run_proc():     symbollist = read in csv file of tickers     symb in symbollist:         webstr = #write connection string         try:             urllib.request.urlopen(webstr) url: page = url.read()             soup = beautifulsoup(page)             if soup.text.find('there no markets results for') == -1:                 tbls = soup.findall('table')                 if len(tbls[9]) > 1:                     expstrings = soup.findall('td', text=true, attrs={'align': 'right'})[0].contents[0].split()                     expdate = datetime.date(int(expstrings[6]), int(currmonth), int(expstrings[5].replace(',', '')))                     calls = extract_options(tbls[9], symb, 'call', expdate)                     puts = extract_options(tbls[13], symb, 'put', expdate)                     optionsrows = optionsrows + calls                     optionsrows = optionsrows + puts          except urllib.error.httperror err:             if err.code == 404:                 pass             else:                 raise     opts = [0] * (len(optionsrows))     option in range(0, len(optionsrows)):     opts[option] = optionsrows[option].forcsv()     #write csv file.     open('c:/optionschains.csv', 'a', newline='') fp:         = csv.writer(fp, delimiter=',')         a.writerows(opts)  if __name__ == '__main__':     run_proc()

there mistakes in abbreviated code have given, little hard understand code. if show more code , check it, easier understand problem.

from code , problem description, have advice share you:

  1. in run_proc() function, read webpage every symbol. if urls same or urls repeated, how read webpages 1 time , write them memory or hardware, analyze page contents every symbol? save

  2. beautifulsoup easy write code, little slow in performance. if lxml can work, save lot time on analyzing webpage contents.

hope help.


Comments

Post a Comment

Popular posts from this blog

css - Which browser returns the correct result for getBoundingClientRect of an SVG element? -

-
this svg contains rect overflows svg element: <svg id='svg' width='10' height='10'> <rect x='-10' y='-10' width='30' height='30'/> </svg> chrome 28 , opera 12 return getboundingclientrect() svg element width , height of 10. firefox 23 reports width , height of 30. correct? jsfiddle the relevant spec cssom , delegates svg spec if svg element not "have associated css layout box". haven't found definition of "having associated css layout box", correct result seem hinge on definition, getbbox returns 30x30 rect in browsers. this firefox bug fixed now, fix in firefox nightlies , should make through firefox 33 released on 14 october 2014. see bug 530985 details.
Read more

gcc - Calling fftR4() in c from assembly -

-
i trying asm fft implementation www.embeddedsignals.com work. running make gives error: undefined reference fftr4(short*, short*, int) at top of asm have .syntax unified .thumb .global fftr4 .type fftr4, %function and there #define's associate c functions arguments registers followed macros fftr4 function uses. after that, fftr4 called .thumb_func fftr4: stmfd sp!, {r4-r11, lr} mov tmp0, #0 // bit reversed counter mov tmp1, #0 .word 0xf3a2fa92 //rbit r3,r2 //rbit r,n lsl r,#3 and c code follows: void fftr4(short *y, short *x, int n); short x[512]; short y[512]; int i; void loop() { (i=0;i<512;i++) x[i]=0; (i=0;i<512;i=i+8) { x[i+0]=16384; x[i+2]=16384; x[i+4]=-16384; x[i+6]=-16384;} fftr4(y, x, 256); serialusb.println(y[128]); serialusb.println(y[129]); serialusb.println(y[384]); serialusb.println(y[385]); // expected results: //y[128]is 8191; y[129] -8190 y[...
Read more

.htaccess - Matching full URL in RewriteCond -

-
i'm trying block post access site (and return 403), except 2 ip's , 1 url ( http://mydomain.com/about-us/contact-us/ ). here's have: rewritecond %{request_method} post rewritecond %{remote_addr} !=1.2.3.4 rewritecond %{remote_addr} !=4.3.2.1 rewritecond %{request_uri} !^http://mydomain.com/about-us/contact-us/$ rewriterule ^ / [f] these rules allowing access ip properly, contact page still not accessible. i'm not sure i'm using request_uri correctly? i've tried variations relative urls rewritecond %{request_uri} !^/about-us/contact-us$ , rewritecond %{request_uri} !^/about-us/contact-us/$ without luck. what doing wrong please? it looks me rule on file name specific. if relax bit, should work. made few other esthetic tweaks. give try: rewritecond %{request_method} post rewritecond %{remote_addr} !^1.2.3.4 rewritecond %{remote_addr} !^4.3.2.1 rewritecond %{request_uri} !about-us/contact-us rewriterule ^ - [f]
Read more