generators in python

1# A generator-function is defined like a normal function, 
2# but whenever it needs to generate a value, 
3# it does so with the yield keyword rather than return. 
4# If the body of a def contains yield, 
5# the function automatically becomes a generator function.
6# Python 3 example
7def grepper_gen():
8  yield "add"
9  yield "grepper"
10  yield "answer"
11grepper = grepper_gen()
12next(grepper)
13> add
14next(grepper)
15> grepper
16next(grepper)
17> answer

1#you can use automation in python using following tools
2#Web Automation use selenium driver
3#GUI Automation use pyautogui tool
4
5#Selenium Automation Example
6#Download chrome driver for Selenium 
7# https://chromedriver.chromium.org/downloads
8
9#############Lanuch WebDriver Function - Begin #############
10#Make sure the downloaded driver is in the same path where your running code
11#else you will get an error.
12
13from selenium import webdriver
14# store the browser driver
15chrome_browser = launch_chromebrowser('chromedriver')
16
17def launch_chromebrowser(browsername):
18    # load the browser driver
19    return webdriver.Chrome(browsername)
20#############Lanuch WebDriver Function - End #############
21

1# Size of generators is a huge advantage compared to list
2import sys
3
4n= 80000
5
6# List
7a=[n**2 for n in range(n)]
8
9# Generator
10# Be aware of the syntax to create generators, lika a list comprehension but with round brakets
11b=(n**2 for n in range(n))
12
13print(f"List: {sys.getsizeof(a)} bits\nGenerator: {sys.getsizeof(b)} bits")

1def count_to_ten_generator():
2  for number in range(10):
3    yield number
4my_generator = count_to_ten_generator()
5first_number = next(my_generator)
6list_or_the_rest = list(my_generator)

1def mygenerator():
2    print('First item')
3    yield 10
4
5    print('Second item')
6    yield 20
7
8    print('Last item')
9    yield 30
10

1mkdir food, food\fruits, food\fruits\apples, food\fruits\oranges, food\vegetables
2