Content-Type: text/x-zim-wiki Wiki-Format: zim 0.4 Creation-Date: 2019-06-16T14:09:48+02:00
Created Sunday 16 June 2019
contain notes/examples of Udemy course "Automate the Boring Stuff with Python Programming"
https://www.udemy.com/automate/
Automating the boring stuff with python
Al Sweigard
https://automatetheboringstuff.com.
opensource book/printable/available on amazon
all expressions are just value and operators
- value: 2 , 5 , 39204
- operators: + , - , *, ...
all data belong to types
- integer
- float
- string
box for some values override the variable
comments ''# this is a comment'' functions are kind of miniprogramm into programm
print() # function to print
input function ''input ()''
len () # len of the string
str ( int (myAge))
- have only 2 values:
- True
- False
- ==
- !=
- <
-
- <=
-
= integers and string are always not equal float values and integer values can be equal
- and
- or
- not
- determinate where block start/finish in base of iden tation
- blank string → Falsey
- 0 is **falsey **
- all other values are Truthy
while spam < 5: spam = spam + 1
- break into loop
- continue into loop
for i in range(5): print (' hello' + str (i))
while loop is equivalent to the fot loop
range (10) →(0,9) range(3,20) → (3,19)
- for loop:
- for i in range (10) → (0,9)
- for i in range (5,20) → (5,19)
- for i in range (0,10,2) → increase by 2
- for i in range (5,1,-1) → decrease by -1 from 5 to 1 you can use break/continue into for loops
- print ()
- input ()
- len () modules contain specific functions : math module / rando module/ ecc to import module:
import random import random, sys, os , math # importing muliple modules
to call function from the module: ''random.randint(1,10) #function randint from module random''
bad prcacticse:
from random import * randint(1,10)
in this case import all from module, and you can use function without indicate the module name
terminate the programm before end of flow
import sys sys.exit( )
pyperclip module
permit to copy/paste text to/from the keyboard
import pyperclip pyperclip.copy('Hello world!') pyperclip.paste()
*need to have *xsel **installed
the modules that come with Python are called the standard library, but you can also intall third-party modules using the pip tool.
kind of mini-programm inside your program get rid of duplicate code
def hello (): print ('Hello world!')
Arguments → the value passed in the function call Parameter → the variable inside the function
def hello (name): print ('Hello ' + name)
def plusOne (number) : return number + 1
the //None value the none type // *every function return value, ever the ***print **function. If the function not have the return statement, the returned value is None
- the print function terminate with newline. You can change this with: ''print('Hello', end='')''
- separation of the strings print ('cat', 'dog', 'mouse', sep= 'ABC')
keyword arguments are optional
variables into function and out of function can have the same name:
- into function → local scope
- out of function → global scope
def spam (): global eggs eggs = 'Hello'
it's possible to handle errors and permit terminate the program if some operation failes and not crash the entire program
try: operation except: error_handler
except block is executed when the try block failed
see guess.py
- a value that contain multiple values
- values in a list also called items
- begins and ends with []
- the indexes start at 0
- values are separated with commas
''['cat', 'dog', 'rat']''
spam = [''['cat', 'dog', 'rat'],[10,20,30,50]] '' spam [1,3] → 50
-1 → last value into the list -2 → second to last item
- spam[1:3] → values from index 1 to index 3 of list
- spam[:2] → from 0 to 2 index value
- spam[1:] → from 1 to end index value
- assignment
- delete:
- del statement
- len
- concatenation
- multiplication
- list () → convert to list
- find if element is into the list:
- 'aaa' in ['bbb', 'awd', 'aaa'] → True
- 'aaa' not in ['bbb', 'awd', 'aaa'] → False
for i in [0,1,2,3] print (i)
this is the sequencies in python
list(range(4)) → [0,1,2,3]
//usefull to populate the big list //
len(myList)
cat = ['fat', 'orange', 'loud'] size, color, disposition = cat color → orange
or ''size, color, disposition = 'skinny', black, 'quiet'''
a = 1 b = 2 a,b=b,a→ a=2, b = 1
spam += 1 spam -= 1 ...
the method is the same thing as a function but it's attached on a certain value
spam = ['hello','hi','howdy','heyas'] spam.index('hello')→ 0
if not find return error message if multiple value present return the first one index
spam = ['hello','hi','howdy','heyas'] spam.append = ('ciao') spam → ['hello','hi','howdy','heyas', 'ciao']
spam.insert(1,'hola') spam → ['hello','hola','hi','howdy','heyas', 'ciao']
spam.remove('hola') spam → ['hello','hi','howdy','heyas', 'ciao']
only the first one is removed
spam = [2,1,5,4] spam.sort() → [1,2,4,5]
also working with strings also in reverse order: ''spam.sort(reverse=True)'' sort method not work with numbers and string into list N.B: ascii-betical order of sort → Uppercase come before lowercase ''spam.sort(key=str.lower) → sort in true alphabetical order''
many operations/methods of list are valid to strings too: index,slice, in, for ... lists are mutable → value can be change string are immutable → the value can NOT be changed
- you can't reassign a value to some character of the string the correct way to change the string is create a new string from the slices
name = 'Zophie a cat' newName = name[0:7] + 'the' + name[8:12] newName → 'Zophie the cat'
- list despite integers are referenced, so when you create new list ad assign the value of the old list. The new and the old one are the same list with the same reference to a memory and when one of two lists change the other one change too, because is the same computer memory
- for this list is a mutable value because it's not stored into variable
- change maded to the list in the local scope are also propogate to the global scope → function receive the copy of the reference and not the copy of the value
the copy module permit to copy the list into the new separate list
import copy spam = ['A','B','C'] chesse = copy.deepcopy(spam)
lists can be write on multiple lines:
spam = [ 'apples' 'oranges', 'bananas']
the long line of code can be written on multiple line with '' :
print('This is the long line of code ...' +
'here is the another piece of code ...')
collection of many values but unlike list indexes, indexes for dictionaries can use many different data types not just integers indexes for the dictionaries are called keys keys with its associated value is called a key value pair
In [24]: myCat = {'size':'fat','color':'gray','disposition':'loud'} In [25]: myCat
Out[25]: {'size': 'fat', 'color': 'gray', 'disposition': 'loud'} In [26]: myCat['size']
Out[26]: 'fat'
indexes not start from 0, but can be any value dictionaries are unordered (comparison of two dictionaries with different order product True)
"in" and "not in" operators working with dictionaries
'''
In [27]: list(myCat.values())
Out[27]: ['fat', 'gray', 'loud']
In [28]: list(myCat.keys())
Out[28]: ['size', 'color', 'disposition']
In [29]: list(myCat.items())
Out[29]: [('size', 'fat'), ('color', 'gray'), ('disposition', 'loud')]
In [30]: myCat.items()
Out[30]: dict_items([('size', 'fat'), ('color', 'gray'), ('disposition', 'loud')])
'''
use in for loops:
'''
In [62]: for k in myCat.values():
...: print (k)
...:
fat
gray
loud
1
In [70]: for k,z in myCat.items():
...: print (k,'-',z)
...:
size - fat
color - gray
disposition - loud
age - 1
'''
'''
In [73]: myCat
Out[73]: {'size': 'fat', 'color': 'gray', 'disposition': 'loud', 'age': 1}
In [74]: myCat.get('age',0)
Out[74]: 1
'''
permit to check if some value exist into the dictionary, without causing error if not. If value not exist, return the default value setted into method
set the dafault value if not exist
'''
In [75]: myCat
Out[75]: {'size': 'fat', 'color': 'gray', 'disposition': 'loud', 'age': 1}
In [76]: myCat.setdefault('color',1)
Out[76]: 'gray'
In [77]: myCat.setdefault('aaa',213)
Out[77]: 213
In [78]: myCat
Out[78]: {'size': 'fat', 'color': 'gray', 'disposition': 'loud', 'age': 1, 'aaa': 213}
'''
''' pprint.pprint (count)
rjtext = pprint.pformat(count) print(rjtext) '''
pprint() permit to display a dictionary value cleanly pformat() function returns a string value of the output
list of dictionaries
In [83]: cat
Out[83]: {'size': 'fat', 'color': 'gray', 'disposition': 'loud', 'age': 1} In [86]: allCats = [] In [88]: allCats.append({'size': 'gray', 'color': 'gray', 'disposition': 'loud', 'age': 7}) In [90]: allCats.append({'size': 'big', 'color': 'red', 'disposition': 'loud', 'age': 7}) In [91]: allCats
Out[91]: [{'size': 'gray', 'color': 'gray', 'disposition': 'loud', 'age': 7}, {'size': 'big', 'color': 'red', 'disposition': 'loud', 'age': 7}]
return the type of some object ''' In [92]: a = 123
In [93]: a
Out[93]: 123
In [94]: type(a)
Out[94]: int
'''
string can be delimeted with '... ' or " ... "
| Escape character | Prints as |
|---|---|
| ' | Single quote |
| " | Double quote |
| \t | Tab |
| \ n | Newline (line break) |
| \ | Backslash |
In [97]: r'That is a Carol's cat'
Out[97]: "That is a Carol\'s cat"
print any backslashes in the string and ignore escape characters
'''jklsdjflkdsf sdhkjfhdskj werwoiejr'''
can perform many operations on the string as on the lists
''' In [101]: spam = 'Hello world!'
In [102]: spam.upper()
Out[102]: 'HELLO WORLD!'
In [103]: spam.lower()
Out[103]: 'hello world!'
'''
''' In [107]: spam = 'hello world!'
In [108]: spam.islower() Out[108]: True '''
- isalpha() - letters only
- isalnum() - letters and number only
- isdecimal() - numbers only
- isspace() - whitespace only
- istitle() - titlecase only (all words inside the string begin with uppercase)
'''
In [109]: spam
Out[109]: 'hello world!'
In [110]: spam.startswith('hello') Out[110]: True
In [111]: spam.endswith('d!')
Out[111]: True
'''
usefull when you need to join a list of strings into a single string
In[112]:','.join(['cats','rats','bats'])
Out[112]: 'cats,rats,bats'
//split string into a list of worlds //
In [113]: 'My name is Simon'.split()
Out[113]: ['My', 'name', 'is', 'Simon']
split by another character:
In [118]: 'My name is Simon'.split('m') Out[118]: ['My na', 'e is Si', 'on']
justify characters (left/right):
In [119]: 'Hello'.rjust(10)
Out[119]: ' Hello'
make string 10 characters long
In [122]: 'Hello'.rjust(15,'*')
Out[122]: '**********Hello' '''
In [123]: 'Hello'.center(20)
Out[123]: ' Hello '
In [124]: 'Hello'.center(20,'=')
Out[124]: '=======Hello========'
'''
remove white space before/after the string
''' In [129]: aaa='Hello '.rjust(10)
In [130]: aaa
Out[130]: ' Hello '
In [131]: aaa.strip()
Out[131]: 'Hello'
'''
it possible to remove not only empty space chacarter
In [132]: 'aadq324sflkf324kaf324'.strip('324')
Out[132]: 'aadq324sflkf324kaf'
''' In [133]: spam = 'Hello there!'
In [134]: spam.replace('e','AAA')
Out[134]: 'HAAAllo thAAArAAA!'
'''
in the string you can use %s for variable and % (var1,var2) out
''' In [135]: name = 'Alex'
In [136]: age = 26
In [137]: 'Hello %s, you are %s' % (name,age)
Out[137]: 'Hello Alex, you are 26'
'''
shebang line into the script:
- windows : #! python3
- os x : #! /usr/bin/env python3
- linux : #! /usr/bin/python3
in windows cmd windows disappear quickly, you have to run pause.exe after the script, it can be done with batch script:
@py c:\hello.py %* @pause
if you don't need a windows to see output: ''@pyw c:\hello.py %*''
import sys print('Hello %s' % sys.argv[2]) print(sys.argv)
- regular expressions are mini-language for specifying text patterns. Writing code to do pattern matching without regula expression is a huge pain.
- regex strings often use \ backslashes (like \d), so they are often raw strings: r'\d'
- import the re module
- call the re.compile() function to create a regex object
- call the regex object's search() method to create a match object
- call the match object's group() method to get the matched string
- \d is the regex for a numeric digit character
''' In [183]: phoneNumRegex = re.compile(r'(\d\d\d)-(\d\d\d-\d\d\d\d)')
In [184]: mo = phoneNumRegex.search('My number is 415-555-4242.')
In [185]: mo.group()
Out[185]: '415-555-4242'
In [186]: mo.group(1)
Out[186]: '415'
In [187]: mo.group(2)
Out[187]: '555-4242'
'''
''' In [188]: batRegex = re.compile(r'Bat(man|mobile|copter|bat)')
In [189]: mo = batRegex.search('Batmobile lost a wheel')
In [190]: mo.group()
Out[190]: 'Batmobile'
'''
- groups are created in regex strings with parentheses
- the first set of parentheses is group 1, the second is 2, ..
- calling group() or group(0) returns the full matching string, group(1) returns group 1's matching string, and so on.
- use ( and ) to match literal parentheses in the regex string
- the | pipe can match one of many possible groups
matching a specific number of repetitions
- (..)?
''' In [199]: import re
In [200]: batRegex = re.compile(r'Bat(wo)?man')
In [201]: mo = batRegex.search('The Adventures of Batman')
In [202]: mo.group()
Out[202]: 'Batman'
In [203]: mo = batRegex.search('The Adventures of Batwoman')
In [204]: mo.group()
Out[204]: 'Batwoman'
'''
- (..)*
''' In [205]: batRegex = re.compile(r'Bat(wo)*man')
In [206]: mo = batRegex.search('The Adventures of Batwoman')
In [207]: mo.group()
Out[207]: 'Batwoman'
In [208]: mo = batRegex.search('The Adventures of Batwowowowoman')
In [209]: mo.group()
Out[209]: 'Batwowowowoman'
'''
- (..)+
- (..){number}
- (..){numberA,numberB}
- match the shortest string possible - not default
- (..){number1,number2}?
''' In [217]: digitRegex = re.compile(r'(\d){3,5}')
In [218]: digitRegex.search('1234567890')
Out[218]: <re.Match object; span=(0, 5), match='12345'>
In [219]: digitRegex = re.compile(r'(\d){3,5}?')
In [220]: digitRegex.search('1234567890')
Out[220]: <re.Match object; span=(0, 3), match='123'>
'''
| Shorthand character class | Represents |
|---|---|
| \d | Any numeric digit from 0 to 9 |
| \D | Any character that is not a numeric digit from 0 to 9 |
| \w | Any letter, numeric digit, or the undescore character. \n (Think of this as matching "word" characters.) |
| \W | Any character that is not a letter, numeric digit or \n the underscore character. |
| \s | Any space, tab, or newline character. \n (Think of this as matching "space" characters.) |
| \S | Any character that is nota a space, tab, or newline. |
| ^ | makes a negative character class \n matching anything not in the brackets [] |
''' In [15]: lyrics = '12 drummers drumming, 11 pipers piping, 10 lords a leaping, 9 ladies danic ...: ng'
In [16]: xmasRegex = re.compile(r'\d+\s\w+')
In [17]: xmasRegex.findall(lyrics)
Out[17]: ['12 drummers', '11 pipers', '10 lords', '9 ladies']
'''
''' In [18]: vowelRegex = re.compile(r'[aeiouAEIOU]') #the same of (a|o|i|..)
In [19]: vowelRegex.findall('Robocop eats baby food.')
Out[19]: ['o', 'o', 'o', 'e', 'a', 'a', 'o', 'o']
In [20]: doubleVowelRegex = re.compile(r'[aeiouAEIOU]{2}')
In [21]: vowelRegex.findall('Robocop eats baby food.')
Out[21]: ['o', 'o', 'o', 'e', 'a', 'a', 'o', 'o']
In [22]: doubleVowelRegex.findall('Robocop eats baby food.')
Out[22]: ['ea', 'oo']
In [23]: consonantsRegex = re.compile(r'[^aeiouAEIOU]')
In [24]: consonantsRegex.findall('Robocop eats baby food.')
Out[24]: ['R', 'b', 'c', 'p', ' ', 't', 's', ' ', 'b', 'b', 'y', ' ', 'f', 'd', '.']
'''
''' In [1]: import re
In [2]: beginsWhithHelloRegex = re.compile(r'^Hello')
In [3]: beginsWhithHelloRegex.search('Hello there!')
Out[3]: <re.Match object; span=(0, 5), match='Hello'>
In [4]: beginsWhithHelloRegex.search('He say: Hello there!') '''
''' In [5]: endsWithWorld =re.compile(r'world!$')
In [6]: endsWithWorld.search('Hello world!')
Out[6]: <re.Match object; span=(6, 12), match='world!'>
In [7]: endsWithWorld.search('Hello world again!') '''
''' In [8]: allDigits = re.compile(r'^\d+$')
In [9]: allDigits.search('33498573948534')
Out[9]: <re.Match object; span=(0, 14), match='33498573948534'>
In [10]: allDigits.search('334985a73948534') '''
'''
In [3]: atRegex = re.compile(r'.at')
In [4]: atRegex.findall('The cat in the hat sat on the flat mat.')
Out[4]: ['cat', 'hat', 'sat', 'lat', 'mat']
In [7]: atRegex = re.compile(r'.{1,2}at')
In [8]: atRegex.findall('The cat in the hat sat on the flat mat.')
Out[8]: [' cat', ' hat', ' sat', 'flat', ' mat']
'''
''' In [12]: nameRegex = re.compile(r'First Name (.) Last Name: (.)')
In [13]: nameRegex = re.compile(r'First Name: (.) Last Name: (.)')
In [14]: nameRegex.findall('First Name: Alex Last Name: Xelk dd')
Out[14]: [('Alex', 'Xelk dd')]
'''
''' In [15]: strin = 'asdkf>'
In [16]: nongreedy = re.compile(r'<(.*?)>')
In [17]: nongreedy.findall(strin)
Out[17]: ['ljasdkl ']
In [18]: ngreedy = re.compile(r'<(.*)>')
In [19]: ngreedy.findall(strin)
Out[19]: ['ljasdkl >asdkf']
'''
re.DOTALL — match as match as possible ''re.compile(r'.*',re.DOTALL)''
re.IGNORECASE or re.I ''re.compile(r'[aeiou]',re.I)''
- ^ the string must start with the pattern
- $ the string must end with the pattern
- ^abc$ the string abc match the pattern
- . (dot) wildcard - matches anything except newlines
''' In [1]: import re
In [2]: namesRegex = re.compile(r'Agent \w+')
In [3]: namesRegex.findall('Agent Alice gave the secret documents to Agent
...: Bob.')
Out[3]: ['Agent Alice', 'Agent Bob']
In [4]: namesRegex.sub('REDACTED','Agent Alice gave the secret documents t
...: o Agent Bob.')
Out[4]: 'REDACTED gave the secret documents to REDACTED.'
In [5]: namesRegex = re.compile(r'Agent (\w)\w*')
In [6]: namesRegex.findall('Agent Alice gave the secret documents to Agent
...: Bob.')
Out[6]: ['A', 'B']
In [7]: namesRegex = re.compile(r'Agent ((\w)\w*)')
In [8]: namesRegex.findall('Agent Alice gave the secret documents to Agent
...: Bob.')
Out[8]: [('Alice', 'A'), ('Bob', 'B')]
In [9]: namesRegex.sub(r'Agent \2****','Agent Alice gave the secret docume
...: nts to Agent Bob.')
Out[9]: 'Agent A**** gave the secret documents to Agent B****.'
'''
In [10]: re.compile(r''' ...: \d\d\d #area code ...: - #sdfsdf ...: \d\d\d\d# last area code''',re.VERBOSE)
Out[10]: re.compile(r'\n\d\d\d #area code\n- #sdfsdf\n\d\d\d\d# last area code', re.UNICODE|re.VERBOSE)
In [11]: re.compile(r''' ...: \d\d\d #area code ...: - #sdfsdf ...: \d\d\d\d# last area code''',re.VERBOSE | re.IGNORECASE | re.DOT ...: ALL )
Recap:
- the sub() regex method : subsitute matches with some other text
- using \1,\2, ... will subsitute group 1,2 etc in the regex pattern
- passing re.VERBOSE lets you add whitespace and comments to the regex string passed to re.compile()
- if you want to pass multiple arguments, combine them with |
see phoneAndEmail.py
helloFIle = open('/tmp/ciao') — read mode
''' In [1]: helloFile = open('/tmp/ciao')
In [2]: helloFile.read()
Out[2]: 'ciao mondo!\nciao mondo!\nciao mondo!\nciao mondo!\nciao mondo!\n'
In [3]: helloFile.close()
In [6]: helloFile.readlines()
Out[6]:
['ciao mondo!\n',
'ciao mondo!\n',
'ciao mondo!\n',
'ciao mondo!\n',
'ciao mondo!\n']
'''
Recap
- open () will return a file object which has reading and writing related methods
- pass 'r' (or nothing) to open() — read monde
- pass 'w' — write mode
- pass 'a' — append mode
- opening a nonexistant filename in write or append mode will create that file
- read () / write ()
- *readlines() //
- //close() — when you are done with the file*
- shelve module can store Python values in a binary file
- shelve.open() — return a dictionary-like shelf value
import shutil
shutli.copy('aa','bb') shutil.copytree() shutil.move() os.unlink() — will delete a file os.rmdir() — will delete a folder (only if it empty) send2trash.send2trash() — will send a file or folder to the recycling bin (import send2trash)
Raise your own excepions with try and except statements so that your program can recover from exceptions that your anticipated, but you can also raise your own exceptions in your code.
''' In [2]: import traceback
In [3]: try:
...: raise Exception('This is the error message.')
...: except:
...: errorFile = open('erroInfo.txt','w')
...: errorFile.write(traceback.format_exc())
...: errorFile.close()
...: print('The traceback info was written to errorInfo.txt.')
...:
The traceback info was written to errorInfo.txt.
'''
is a sanity check to make sure your code isn't doing something obviously wrong, these sanity checks are performed by assert statements. If the sanity checks fails, then an AssertionError exception is raised. In code, an assert statement consists of the following:
- the assert keywoard
- a condition
- a comma
- a string to display when the condition is False
An assert statement says, "I assert that this condition holds true and if not, there is a bug somewhere in the program." The code should not handle assert statements with try and except; if an assert fails, your progrm should crash. Assertations are for programmer errors, not user errors. For errors that can be recovered from (such as a file not being found or the user entering invalid data), raise an exceptio instead of detecting it with an assert statement.
to run program without assertations "python -O myprogra.py"
enable logging in your program with:
import logging logging.basicConfig(level=logging.DEBUG, format=' %(asctime)s - %(levelname)s -%(message)s')
print debug message
logging.debug('Start of program')
disabling
logging.disable(logging.CRITICAL)--> disable all message of CRITICAL level and below --> disable all messages
various levels of log
- debug
- info
- warning
- error
- critical
logging to a file
logging.basicConfig(filename='myProgramLog.txt', level=logging.DEBUG, format=' %(asctime)s - %(levelname)s - %(message)s')
the requests moduile is a third-party module for downloading web pages and files requests.get() returns a Response object the raise_for_status() response method will raise an exception if the download failed you can save a downloaded file to your hard drive with calls to the iter_content() method
pip install beautifulsoup4 import bs4
- web pages are plaintext files formatted as HTML
- HTML can be paresed with the BeautifulSoup module
- BeatifulSoup is imported with the name bs4
- pass teh string with the HTML to the bs4.BeautifulSoup() function to get a Soup object
- the soup object has a select() method that can be passed a string og the CSS selector for an HTML tag
- you can get a CSS selector string from the browser's developer tools by right-click the element and selecting Copy CSS Path
- the select() method will return a list of matching Element objects.
permit to run browser with python → run javascript/authontication/ecc → slow
''pip install selenium''
''' In [15]: browser = webdriver.Firefox()
In [16]: browser.get('https://automatetheboringstuff.com')
In [17]: elem = browser.find_element_by_css_selector('.main > div:nth-child(1) > ul:nth-child(
...: 19) > li:nth-child(1) > a:nth-child(1)')
In [18]: elem.click()
In [29]: searchElem = browser.find_element_by_class_name('gLFyf')
In [30]: searchElem.send_keys('ciao')
In [31]: searchElem.send_keys('ciao darwin')
In [32]: searchElem.send_keys('aaa')
In [33]: searchElem.send_keys('adlajsd')
In [34]: searchElem.submit()
In [35]: browser.back()
In [36]: browser.forward()
In [37]: browser.refresh()
^[[A
In [38]: browser.quit()
'''
- to import selenium=, you need to run: from selenium import webdrivers
- to open the browser, run: browser = webdriver.Firefox()
- to send the browser to a URL, run: beowser.get
- the browser.find_elements_by_css_selector() method will return a list of WebElement objects
- WebElement objects have a text variable that contains the element's HTML in a string
- the clic() method will clock on an element in the browser
- the send_key() method will type into a specific element in the browser
- the submit() method will simulate clicking on the Submit button for a form
- the browser can also be controlled with these method: back(), forward(), refresh(), quit().