from selenium import webdriver

driver = webdriver.Chrome()
driver.get('http://web.whatsapp.com')

name = input('Enter the name: ')
msg = input('message: ')
count = int(input('Enter the count: '))

input('Enter anything after scanning QR code')

user = driver.find_element_by_xpath('//span[@title = "{}"]'.format(name))
user.click()

msg_box = driver.find_element_by_class_name('_2i7Ej')

for i in range(count):
    msg_box.send_keys(msg)
    button = driver.find_element_by_class_name('hnQHL')
    buton.click()