PERMISSION DENIDED ERRNO 13

[ambush]

HI

I am trying to install flake8 on virtualenv but i was unable to do so due to following error

Exception:

Error:
Traceback (most recent call last):
  File "/home/sai/calculator/lib/python3.6/site-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/home/sai/calculator/lib/python3.6/site-packages/pip/commands/install.py", line 360, in run
    prefix=options.prefix_path,
  File "/home/sai/calculator/lib/python3.6/site-packages/pip/req/req_set.py", line 784, in install
    **kwargs
  File "/home/sai/calculator/lib/python3.6/site-packages/pip/req/req_install.py", line 851, in install
    self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
  File "/home/sai/calculator/lib/python3.6/site-packages/pip/req/req_install.py", line 1064, in move_wheel_files
    isolated=self.isolated,
  File "/home/sai/calculator/lib/python3.6/site-packages/pip/wheel.py", line 345, in move_wheel_files
    clobber(source, lib_dir, True)
  File "/home/sai/calculator/lib/python3.6/site-packages/pip/wheel.py", line 323, in clobber
    shutil.copyfile(srcfile, destfile)
  File "/usr/lib/python3.6/shutil.py", line 121, in copyfile
    with open(dst, 'wb') as fdst:
PermissionError: [Errno 13] Permission denied: '/home/sai/calculator/lib/python3.6/site-packages/__pycache__/mccabe.cpython-36.pyc'

I need to know what are Probable solutions for the problem.Please let me know

[metulburr]

sudo the command
if it is the previous command

sudo !!

[snippsat]

Should not need to use sudo as virtual environment should be user based.

I am trying to install flake8 on virtualenv

How are you creating the virtual environment,is calculator your environment folder do you see see (calculator)?
Now also virtual environment is build into python trough venv.
Example:

tom@tom:~$ python -m venv my_env
tom@tom:~$ cd my_env
tom@tom:~/my_env$ source bin/activate

# Active see (my_env)
(my_env) tom@tom:~/my_env$ pip install flake8
Collecting flake8  
Installing collected packages: pyflakes, mccabe, pycodestyle, flake8
Successfully installed flake8-3.6.0 mccabe-0.6.1 pycodestyle-2.4.0 pyflakes-2.0.0

(my_env) tom@tom:~/my_env$ python 
Python 3.7.2 (default, Jan 16 2019, 23:14:35) 
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import flake8
>>> flake8.__version__
'3.6.0'
>>> exit()