pip3에 Selenium을 설치하는 동안 오류가 발생했습니다.

셀레늄을 설치하려고하는데 문제가있는 것 같습니다.

pip3 install -U selenium을 실행했는데 다음과 같은 결과가 나타납니다.

    Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python3.5/site-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/usr/local/lib/python3.5/site-packages/pip/commands/install.py", line 317, in run
    prefix=options.prefix_path,
  File "/usr/local/lib/python3.5/site-packages/pip/req/req_set.py", line 742, in install
    **kwargs
  File "/usr/local/lib/python3.5/site-packages/pip/req/req_install.py", line 831, in install
    self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
  File "/usr/local/lib/python3.5/site-packages/pip/req/req_install.py", line 1032, in move_wheel_files
    isolated=self.isolated,
  File "/usr/local/lib/python3.5/site-packages/pip/wheel.py", line 378, in move_wheel_files
    clobber(source, dest, False, fixer=fixer, filter=filter)
  File "/usr/local/lib/python3.5/site-packages/pip/wheel.py", line 317, in clobber
    ensure_dir(destdir)
  File "/usr/local/lib/python3.5/site-packages/pip/utils/__init__.py", line 83, in ensure_dir
    os.makedirs(path)
  File "/usr/local/Cellar/python3/3.5.2_2/Frameworks/Python.framework/Versions/3.5/lib/python3.5/os.py", line 231, in makedirs
    makedirs(head, mode, exist_ok)
  File "/usr/local/Cellar/python3/3.5.2_2/Frameworks/Python.framework/Versions/3.5/lib/python3.5/os.py", line 231, in makedirs
    makedirs(head, mode, exist_ok)
  File "/usr/local/Cellar/python3/3.5.2_2/Frameworks/Python.framework/Versions/3.5/lib/python3.5/os.py", line 231, in makedirs
makedirs(head, mode, exist_ok)
  File "/usr/local/Cellar/python3/3.5.2_2/Frameworks/Python.framework/Versions/3.5/lib/python3.5/os.py", line 241, in makedirs
    mkdir(name, mode)
PermissionError: [Errno 13] Permission denied: '/usr/local/selenium'

이 메시지에도 불구하고 python3에서 셀레늄을 계속 실행하고 실행할 수 있습니다.

from selenium import web driver
browser = webdriver.Firefox()

돌아올 것이다

Traceback (most recent call last):
  File "/usr/local/lib/python3.5/site-packages/selenium/webdriver/common/service.py", line 64, in start
stdout=self.log_file, stderr=self.log_file)
  File "/usr/local/Cellar/python3/3.5.2_2/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 947, in __init__
restore_signals, start_new_session)
  File "/usr/local/Cellar/python3/3.5.2_2/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 1551, in _execute_child
raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'geckodriver'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.5/site-packages/selenium/webdriver/firefox/webdriver.py", line 135, in __init__
self.service.start()
  File "/usr/local/lib/python3.5/site-packages/selenium/webdriver/common/service.py", line 71, in start
os.path.basename(self.path), self.start_error_message)
selenium.common.exceptions.WebDriverException: Message: 'geckodriver' executable needs to be in PATH.

내가 무엇을해야 하나?