I want to use Selenium to start Firefox.

 from selenium import geckodriver

ImportError Traceback (most recent call last)
/tmp/ipykernel_3513/2951967038.py in<module>
---->1 from selenium import geckodriver

ImportError: cannot import name 'geckodriver' from 'selenium' (/home/yusuke/anaconda3/envs/dev/lib/python3.9/site-packages/selenium/_init__.py)

from time import sleep
browser=geckodriver.Firefox()

 from selenium import webdriver
from time import sleep
browser=webdriver.Firefox()
---------------------------------------------------------------------------
FileNotFoundError Traceback (most recent call last)
~/anaconda3/envs/dev/lib/python3.9/site-packages/selenium/webdriver/common/service.py in start(self)
     71cmd.extend(self.command_line_args())
--- >72self.process=subprocess.Popen(cmd, env=self.env,
     73close_fds=platform.system()!='Windows',

~/anaconda3/env/dev/lib/python3.9/subprocess.py in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creation_logs, restoration, restaurant, restaurant_news, resume, store, resume, store_s
    950 
-->951self._execute_child(args, executable, preexec_fn, close_fds,
    952pass_fds, cwd, env,

~/anaconda3/env/dev/lib/python3.9/subprocess.py in_execute_child(self,args,executable,preexec_fn,close_fds,pass_fds,cwd,env,startupinfo,creationflags,shell,p2cred,c2cred,c2cred,cred,c2cred,cred,prite,prite,red,prite,red,red,red,red,red,red,red,red,red,red,red,red,red,red,red,red,red,red,red,
   1820 err_msg = os.sterror(errno_num)
->1821 raise child_exception_type(errno_num, err_msg, err_filename)
   1822 raise child_exception_type(err_msg)

FileNotFoundError: [Errno2] No such file or directory: 'geckodriver'

During handling of the above exception, another exception occurred:

WebDriverException Traceback (most recent call last)
/tmp/ipykernel_3513/4270241205.py in<module>
---->1 browser=webdriver.Firefox()

~/anaconda3/envs/dev/lib/python3.9/site-packages/selenium/webdriver/firefox/webdriver.py in __init_(self,firefox_profile,firefox_binary,timeout,capabilities,proxy,executable_path,options,service_log_paths,firefoil_service_paths,firefires,service_paths,firefirections,service_paths,firefires,firefirections
    162 service_args = service_args,
    163 log_path = service_log_path )
-->164self.service.start()
    165 
    166 capabilities.update(options.to_capabilities())

~/anaconda3/envs/dev/lib/python3.9/site-packages/selenium/webdriver/common/service.py in start(self)
     79 except OSError as err:
     80 if err.errno==errno.ENOENT:
--- >81 raise WebDriverException(
     82"%s' executable needs to be in PATH.%s"%(
     83 os.path.basename(self.path), self.start_error_message)

WebDriverException: Message: 'geckodriver' executable needs to be in PATH.