How to delete data from csv file using python - python

I am scraping a website for the course number and the course name. But if a course number does not have a name or vice versa, the data should be skipped from the final output. I do not know how to do that.
from bs4 import BeautifulSoup
from urllib import urlopen
import csv
source = urlopen('https://www.rit.edu/study/computing-security-bs')
csv_file1 = open('scrape.csv', 'w')
csv_writer = csv.writer(csv_file1)
csv_writer.writerow(['Course Number', 'Course Name'])
soup = BeautifulSoup(source, 'lxml')
table = soup.find('div', class_='processed-table')
#print(table)
curriculum = table.find('curriculum')
#print(curriculum.prettify())
next = curriculum.find('table', class_='table-curriculum')
#print(next.prettify())
for course_num in next.find_all('tr', class_='hidden-row rows-1'):
num = course_num.find_all('td')[0]
real = num.get_text()
# print(real)
realstr = real.encode('utf-8')
name = course_num.find('div', class_='course-name')
realname = name.get_text()
# print(realname)
realnamestr = realname.encode('utf-8')
csv_writer.writerow([realstr, realnamestr])
csv_file1.close()
This is my csv
csv
I want to get rid of the last 4 rows.

As #zvone suggested, a continue will do the job here. Writing this answer as you mentioned you are not aware of the keyword.
Before, csv_writer.writerow([realstr, realnamestr]) just put an if to check the realstr and continue:
if realstr.stip() == "":
continue
I think you should still go through the continue, break and else keywords and how they can be helpful in controlling your loops.
Another approach would be to put data into csv_writer only when realstr has some value. So:
if realstr.strip != "":
csv_writer.writerow([realstr, realnamestr])

Related

Write data into csv

I am crawling data from Wikipedia and it works so far. I can display it on the terminal, but I can't write it the way I need it into a csv file :-/
The code is pretty long, but I paste it here anyway and hope that somebody can help me.
import csv
import requests
from bs4 import BeautifulSoup
def spider():
url = 'https://de.wikipedia.org/wiki/Liste_der_Gro%C3%9F-_und_Mittelst%C3%A4dte_in_Deutschland'
code = requests.get(url).text # Read source code and make unicode
soup = BeautifulSoup(code, "lxml") # create BS object
table = soup.find(text="Rang").find_parent("table")
for row in table.find_all("tr")[1:]:
partial_url = row.find_all('a')[0].attrs['href']
full_url = "https://de.wikipedia.org" + partial_url
get_single_item_data(full_url) # goes into the individual sites
def get_single_item_data(item_url):
page = requests.get(item_url).text # Read source code & format with .text to unicode
soup = BeautifulSoup(page, "lxml") # create BS object
def getInfoBoxBasisDaten(s):
return str(s) == 'Basisdaten' and s.parent.name == 'th'
basisdaten = soup.find_all(string=getInfoBoxBasisDaten)[0]
basisdaten_list = ['Bundesland', 'Regierungsbezirk:', 'Höhe:', 'Fläche:', 'Einwohner:', 'Bevölkerungsdichte:',
'Postleitzahl', 'Vorwahl:', 'Kfz-Kennzeichen:', 'Gemeindeschlüssel:', 'Stadtgliederung:',
'Adresse', 'Anschrift', 'Webpräsenz:', 'Website:', 'Bürgermeister', 'Bürgermeisterin',
'Oberbürgermeister', 'Oberbürgermeisterin']
with open('staedte.csv', 'w', newline='', encoding='utf-8') as csvfile:
fieldnames = ['Bundesland', 'Regierungsbezirk:', 'Höhe:', 'Fläche:', 'Einwohner:', 'Bevölkerungsdichte:',
'Postleitzahl', 'Vorwahl:', 'Kfz-Kennzeichen:', 'Gemeindeschlüssel:', 'Stadtgliederung:',
'Adresse', 'Anschrift', 'Webpräsenz:', 'Website:', 'Bürgermeister', 'Bürgermeisterin',
'Oberbürgermeister', 'Oberbürgermeisterin']
writer = csv.DictWriter(csvfile, fieldnames=fieldnames, delimiter=';', quotechar='|', quoting=csv.QUOTE_MINIMAL, extrasaction='ignore')
writer.writeheader()
for i in basisdaten_list:
wanted = i
current = basisdaten.parent.parent.nextSibling
while True:
if not current.name:
current = current.nextSibling
continue
if wanted in current.text:
items = current.findAll('td')
print(BeautifulSoup.get_text(items[0]))
print(BeautifulSoup.get_text(items[1]))
writer.writerow({i: BeautifulSoup.get_text(items[1])})
if '<th ' in str(current): break
current = current.nextSibling
print(spider())
The output is incorrect in 2 ways. The cells are their right places and only one city is written, all others are missing. It looks like this:
But it should look like this + all other cities in it:
'... only one city is written ...': You call get_single_item_data for each city. Then inside this function you open the output file with the same name, in the statement with open('staedte.csv', 'w', newline='', encoding='utf-8') as csvfile: which will overwrite the output file each time you call the function.
Each variable is written to a new row: In the statement writer.writerow({i: BeautifulSoup.get_text(items[1])}) you write the value for one variable to a row. What you need to do instead is to make a dictionary for values before you start looking for page values. As you accumulate the values from the page you shove them into the dictionary by field name. Then after you have found all of the values available you call writer.writerow.

beautifulsoup to csv: putting paragraph of text into one line

I have a bunch of web text that I'd like to scrape and export to a csv file. The problem is that the text is split over multiple lines on the website and that's how beautifulsoup reads it. When I export to csv, all the text goes into one cell but the cell has multiple lines of text. When I try to read the csv into another program, it interprets the multiple lines in a way that yields a nonsensical dataset. The question is, how do I put all the text into a single line after I pull it with beautifulsoup but before I export to csv?
Here's a simple working example demonstrating the problem of multiple lines (in fact, the first few lines in the resulting csv are blank, so at first glance it may look empty):
import csv
import requests
from bs4 import BeautifulSoup
def main():
r = requests.get("https://www.econometricsociety.org/publications/econometrica/2017/03/01/search-yield")
soup = BeautifulSoup(r.text,"html.parser")
with open('Temp.csv', 'w', encoding='utf8', newline='') as f:
writer = csv.writer(f,delimiter=",")
abstract=soup.find("article").text
writer.writerow([abstract])
if __name__ == '__main__':
main()
UPDATE: there have been some good suggestions, but it's still not working. The following code still produces a csv file with line breaks in a cell:
import csv
import requests
from bs4 import BeautifulSoup
with open('Temp.csv', 'w', encoding='utf8', newline='') as f:
writer = csv.writer(f,delimiter=',')
r = requests.get("https://www.econometricsociety.org/publications/econometrica/2017/03/01/search-yield")
soup = BeautifulSoup(r.text,'lxml')
find_article = soup.find('article')
find_2para = find_article.p.find_next_sibling("p")
find_largetxt = find_article.p.find_next_sibling("p").nextSibling
writer.writerow([find_2para,find_largetxt])
Here's another attempt based on a different suggestion. This one also ends up producing a line break in the csv file:
import csv
import requests
from bs4 import BeautifulSoup
def main():
r = requests.get("https://www.econometricsociety.org/publications/econometrica/2017/03/01/search-yield")
soup = BeautifulSoup(r.text,"html.parser")
with open('Temp.csv', 'w', encoding='utf8', newline='') as f:
writer = csv.writer(f,delimiter=",")
abstract=soup.find("article").get_text(separator=" ", strip=True)
writer.writerow([abstract])
if __name__ == '__main__':
main()
Change your abstract = ... line into:
abstract = soup.find("article").get_text(separator=" ", strip=True)
It'll separate each line using the separator parameter (in this case It'll separate the strings with an empty space.
The solution that ended up working for me is pretty simple:
abstract=soup.find("article").text.replace("\t", "").replace("\r", "").replace("\n", "")
That gets rid of all line breaks.
r = requests.get("https://www.econometricsociety.org/publications/econometrica/2017/03/01/search-yield")
soup = BeautifulSoup(r.text,'lxml') # I prefer using xml parser
find_article = soup.find('article')
# Next line how to find The title in this case: Econometrica: Mar 2017, Volume 85, Issue 2
find_title = find_article.h3
# find search yeild
find_yeild = find_article.h1
#first_paragraph example : DOI: 10.3982/ECTA14057 p. 351-378
find_1para = find_article.p
#second p example : David Martinez‐Miera, Rafael Repullo
find_2para = find_article.p.find_next_sibling("p")
#find the large text area using e.g. 'We present a model of the relationship bet...'
find_largetxt = find_article.p.find_next_sibling("p").nextSibling
I used a variety of methods of getting to the text area you wish just for the purpose of education(you can use .text on each of these to get the text without tags or you can use Zroq's method.
But you can write each one of these into the file by doing for example
writer.writerow(find_title.text)

Shaking off duplicates while parsing

I've made a parser written in python which is doing it's job perfectly except for some duplicates coming along. Moreover, when I open csv file I can see that every result is surrounded by square braces. Is there any workaround to get rid of duplicates data and square braces on the fly? Here is what I tried with:
import csv
import requests
from lxml import html
def parsingdata(mpg):
data = set()
outfile=open('RealYP.csv','w',newline='')
writer=csv.writer(outfile)
writer.writerow(["Name","Address","Phone"])
pg=1
while pg<=mpg:
url="https://www.yellowpages.com/search?search_terms=Coffee%20Shops&geo_location_terms=Los%20Angeles%2C%20CA&page="+str(pg)
page=requests.get(url)
tree=html.fromstring(page.text)
titles = tree.xpath('//div[#class="info"]')
items = []
for title in titles:
comb = []
Name = title.xpath('.//span[#itemprop="name"]/text()')
Address = title.xpath('.//span[#itemprop="streetAddress" and #class="street-address"]/text()')
Phone = title.xpath('.//div[#itemprop="telephone" and #class="phones phone primary"]/text()')
try:
comb.append(Name[0])
comb.append(Address[0])
comb.append(Phone[0])
except:
continue
items.append(comb)
pg+=1
for item in items:
writer.writerow(item)
parsingdata(3)
Now it is working fine.
Edit: Rectified portion taken from bjpreisler
This script removes dups when I am working with a .csv file. Check if this works for you :)
with open(file_out, 'w') as f_out, open(file_in, 'r') as f_in:
# write rows from in-file to out-file until all the data is written
checkDups = set() # set for removing duplicates
for line in f_in:
if line in checkDups: continue # skip duplicate
checkDups.add(line)
f_out.write(line)
You are currently writing a list (items) to the csv which is why it is in brackets. To avoid this, use another for loop that could look like this:
for title in titles:
comb = []
Name = title.xpath('.//span[#itemprop="name"]/text()')
Address = title.xpath('.//span[#itemprop="streetAddress" and #class="street-address"]/text()')
Phone = title.xpath('.//div[#itemprop="telephone" and #class="phones phone primary"]/text()')
if Name:
Name = Name[0]
if Address:
Address = Address[0]
if Phone:
Phone = Phone[0]
comb.append(Name)
comb.append(Address)
comb.append(Phone)
print comb
items.append(comb)
pg+=1
for item in items:
writer.writerow(item)
parsingdata(3)
This should write each item separately to your csv. It turns out the items you were appending to comb were lists themselves, so this extracts them.
And the concise version of this scraper I found lately is:
import csv
import requests
from lxml import html
url = "https://www.yellowpages.com/search?search_terms=Coffee%20Shops&geo_location_terms=Los%20Angeles%2C%20CA&page={0}"
def parsingdata(link):
outfile=open('YellowPage.csv','w',newline='')
writer=csv.writer(outfile)
writer.writerow(["Name","Address","Phone"])
for page_link in [link.format(i) for i in range(1, 4)]:
page = requests.get(page_link).text
tree = html.fromstring(page)
for title in tree.xpath('//div[#class="info"]'):
Name = title.findtext('.//span[#itemprop="name"]')
Address = title.findtext('.//span[#itemprop="streetAddress"]')
Phone = title.findtext('.//div[#itemprop="telephone"]')
print([Name, Address, Phone])
writer.writerow([Name, Address, Phone])
parsingdata(url)

How to write a new column to csv when webscraping?

I'd like to get some quick help on writing this webscraping program. So far it's scraping things correctly, but I'm having trouble writing it to a csv file.
I'm scraping two things from each reviewer: Review score AND written review
I'd like to write the review score into the first column, and the written review into the second column. However, writerow only does it row by row.
Appreciate any help on this! :)
import os, requests, csv
from bs4 import BeautifulSoup
# Get URL of the page
URL = ('https://www.tripadvisor.com/Attraction_Review-g294265-d2149128-Reviews-Gardens_by_the_Bay-Singapore.html')
with open('GardensbytheBay.csv', 'w', newline='') as csvfile:
writer = csv.writer(csvfile)
# Looping until the 5th page of reviews
for pagecounter in range(3):
# Request get the first page
res = requests.get(URL)
res.raise_for_status
# Download the html of the first page
soup = BeautifulSoup(res.text, "html.parser")
# Match it to the specific tag for all 5 ratings
reviewElems = soup.findAll('img', {'class': ['sprite-rating_s_fill rating_s_fill s50', 'sprite-rating_s_fill rating_s_fill s40', 'sprite-rating_s_fill rating_s_fill s30', 'sprite-rating_s_fill rating_s_fill s20', 'sprite-rating_s_fill rating_s_fill s10']})
reviewWritten = soup.findAll('p', {'class':'partial_entry'})
if reviewElems:
for row, rows in zip(reviewElems, reviewWritten):
review_text = row.attrs['alt'][0]
review2_text = rows.get_text(strip=True).encode('utf8', 'ignore').decode('latin-1')
writer.writerow([review_text])
writer.writerow([review2_text])
print('Writing page', pagecounter + 1)
else:
print('Could not find clue.')
# Find URL of next page and update URL
if pagecounter == 0:
nextLink = soup.select('a[data-offset]')[0]
elif pagecounter != 0:
nextLink = soup.select('a[data-offset]')[1]
URL = 'http://www.tripadvisor.com' + nextLink.get('href')
print('Download complete')
You can put the review score and text in the same row but different columns with:
writer.writerow([review_text, review2_text])
Your initial approach takes each of the items as a separate row and writes them in succession which is not what you want.
You can use pandas dataFrame:
import pandas as pd
import numpy as np
csv_file = pd.read_csv('GardensbytheBay.csv')
csv_file.insert(idx, cloname, value)
csv_input.to_csv('output.csv', index=False)

Loop in python script with xpath. Why do I only get results form last url?

Why do I only get the results form the last url?
The idea is that I get a list of results of both urls.
Also, with the printing in csv I get eacht time an empty row. How do I remove this row?
import csv
import requests
from lxml import html
import urllib
TV_category = ["_108-tot-127-cm-43-tot-50-,98952,501090","_128-tot-150-cm-51-tot-59-,98952,501091"]
url_pattern = 'http://www.mediamarkt.be/mcs/productlist/{}.html?langId=-17'
for item in TV_category:
url = url_pattern.format(item)
page = requests.get(url)
tree = html.fromstring(page.content)
outfile = open("./tv_test1.csv", "wb")
writer = csv.writer(outfile)
rows = tree.xpath('//*[#id="category"]/ul[2]/li')
for row in rows:
price = row.xpath('normalize-space(div/aside[2]/div[1]/div[1]/div/text())')
product_ref = row.xpath('normalize-space(div/div/h2/a/text())')
writer.writerow([product_ref,price])
As I explained in the question's comments, you need to put the second for loop inside (at the end) the first one. Otherwise, only the last rows results will be saved/written to the CSV-format file.
You don't need to open the file in each loop (a with statement will close it automagically). It is, as well, important to highlight that if you open a file with write flags it will overwrite, and if it's inside a loop it will overwrite each time it's opened.
I'd refactor your code as follows:
import csv
import requests
from lxml import html
import urllib
TV_category = ["_108-tot-127-cm-43-tot-50-,98952,501090","_128-tot-150-cm-51-tot-59-,98952,501091"]
url_pattern = 'http://www.mediamarkt.be/mcs/productlist/{}.html?langId=-17'
with open("./tv_test1.csv", "wb") as outfile:
writer = csv.writer(outfile)
for item in TV_category:
url = url_pattern.format(item)
page = requests.get(url)
tree = html.fromstring(page.content)
rows = tree.xpath('//*[#id="category"]/ul[2]/li')
for row in rows:
price = row.xpath('normalize-space(div/aside[2]/div[1]/div[1]/div/text())')
product_ref = row.xpath('normalize-space(div/div/h2/a/text())')
writer.writerow([product_ref,price])

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