Section 13.18 Write Code Exercises
Checkpoint 13.18.1.
Complete the following code that retrieves the file ‘romeo.txt' from. Make changes to line 4 and 5.
import socket
mysock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
mysock.connect(('____', __))
cmd = '____ ________________________ HTTP/1.0\r\n\r\n'.encode()
mysock.send(cmd)
while True:
data = mysock.recv(512)
if len(data) < 1:
break
print(data.decode(),end='')
mysock.close()
Solution.Complete the following code that retrieves the file ‘romeo.txt' from. Make changes to line 4 and 5.
import socket
mysock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
mysock.connect(('data.pr4e.org', 80))
cmd = 'GET http://data.pr4e.org/romeo.txt HTTP/1.0\r\n\r\n'.encode()
mysock.send(cmd)
while True:
data = mysock.recv(512)
if len(data) < 1:
break
print(data.decode(),end='')
mysock.close()
Checkpoint 13.18.2.
Complete the following code to extract an image ‘cover3.jpg' from the URL ‘
http://data.pr4e.org/cover3.jpg 1 ' and host ‘data.pr4e.org'. There are 5 empty spaces.
import socket
HOST = '________'
PORT = 80
mysock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
mysock.connect((____, ____))
mysock.sendall(b'___ __________________ HTTP/1.0\r\n\r\n')
count = 0
picture = b""
while True:
data = mysock.recv(5120)
if len(data) < 1: break
#time.sleep(0.25)
count = count + len(data)
print(len(data), count)
picture = picture + data
mysock.close()
pos = picture.find(b"\r\n\r\n")
picture = picture[pos+4:]
fhand = open("stuff.jpg", "wb")
fhand.write(picture)
fhand.close()
Checkpoint 13.18.3.
import urllib.request
fhand = urllib.request.urlopen('_________________')
Solution.Complete the following code that retrieves the text from ‘http://data.pr4e.org/clown.txt' and prints the frequency of each word.
import urllib.request
fhand = urllib.request.urlopen('http://data.pr4e.org/clown.txt')
for line in fhand:
words = line.decode().strip()
print(words)
for word in words:
counts[word] = counts.get(word, 0) + 1
print(counts)
Checkpoint 13.18.4.
import urllib.request
Checkpoint 13.18.5.
import urllib.request, urllib.parse, urllib.error
Solution.Write a program to store image file from ‘http://data.pr4e.org/cover.jpg' to your disk.
import urllib.request, urllib.parse, urllib.error
img = urllib.request.urlopen('http://data.pr4e.org/cover.jpg').read()
fhand = open('cover.jpg', 'wb')
fhand.write(img)
fhand.close()
Checkpoint 13.18.6.
Complete the following program to extract all url from the webpage using regex.
import urllib.request, urllib.parse, urllib.error
import re
url = "https://www.nytimes.com"
html = _______________________
links = _______(b'href="(http[s]?://.*?)"', html)
Checkpoint 13.18.7.
import urllib.request, urllib.parse, urllib.error
txt = urllib.request.urlopen('___________________')
size = 0
while True:
info = txt.read(100000)
if len(info) < 1: break
size = size + len(info)
Solution.Write a program that retrives a txt file from ‘https://www.gutenberg.org/files/1342/1342-0.txt' in several blocks of 100,000 characters, joins them and saves as ‘prideandprejudice.txt' to disk and prints number of characters.
import urllib.request, urllib.parse, urllib.error
txt = urllib.request.urlopen('https://www.gutenberg.org/files/1342/1342-0.txt')
fhand = open('prideandprejudice.txt', 'wb')
size = 0
while True:
info = txt.read(100000)
if len(info) < 1: break
size = size + len(info)
fhand.write(info)
print(size, 'characters copied.')
fhand.close()
Checkpoint 13.18.8.
import urllib.request, urllib.parse, urllib.error
Checkpoint 13.18.9.
Complete the following code to print all the image sources from the webpage. Use ‘img' and ‘src' as tags.
import requests
from bs4 import BeautifulSoup
url = "https://www.nytimes.com/"
resp = requests.get(url)
soup = BeautifulSoup(resp.content, 'html.parser')
Solution.Complete the following code to print all the image sources from the webpage. Use ‘img' and ‘src' as tags.
import requests
from bs4 import BeautifulSoup
url = "https://www.nytimes.com/"
resp = requests.get(url)
soup = BeautifulSoup(resp.content, 'html.parser')
tags = soup('img')
for tag in tags:
print(tag.get('src', None))
Checkpoint 13.18.10.
Write code that extracts data from several parts of the ‘a' tag from “
http://www.dr-chuck.com/page1.htm 7 ” using BeautifulSoup and html.parser and print the tag, href, contents as well as all the attributes.
import requests
from bs4 import BeautifulSoup
http://data.pr4e.org/cover3.jpg
http://data.pr4e.org/clown.txt
http://data.pr4e.org/intro-short.txt
http://data.pr4e.org/cover.jpg
https://www.gutenberg.org/files/1342/1342-0.txt
https://www.gutenberg.org/files/16/16-0.txt
http://www.dr-chuck.com/page1.htm
