rahul@rahul-Inspiron-7373:~/code/zenoti_rest (develop)*$ pip install virtualenv
Traceback (most recent call last):
  File "/usr/bin/pip", line 11, in <module>
    sys.exit(main())
TypeError: 'module' object is not callable
rahul@rahul-Inspiron-7373:~/code/zenoti_rest (develop)*$ pip install --upgrade pip
Traceback (most recent call last):
  File "/usr/bin/pip", line 11, in <module>
    sys.exit(main())
TypeError: 'module' object is not callable
rahul@rahul-Inspiron-7373:~/code/zenoti_rest (develop)*$ pip install virtualenv
Traceback (most recent call last):
  File "/usr/bin/pip", line 11, in <module>
    sys.exit(main())
TypeError: 'module' object is not callable
rahul@rahul-Inspiron-7373:~/code/zenoti_rest (develop)*$ pip3 install virtualenv
Traceback (most recent call last):
  File "/usr/bin/pip3", line 11, in <module>
    sys.exit(main())
TypeError: 'module' object is not callable
rahul@rahul-Inspiron-7373:~/code/zenoti_rest (develop)*$ pip --version
Traceback (most recent call last):
  File "/usr/bin/pip", line 11, in <module>
    sys.exit(main())
TypeError: 'module' object is not callable
rahul@rahul-Inspiron-7373:~/code/zenoti_rest (develop)*$ pip3
Traceback (most recent call last):
  File "/usr/bin/pip3", line 11, in <module>
    sys.exit(main())
TypeError: 'module' object is not callable
rahul@rahul-Inspiron-7373:~/code/zenoti_rest (develop)*$ sudo aptitude install python3-pip python-pip
python3-pip is already installed at the requested version (18.1-5)
python-pip is already installed at the requested version (18.1-5)
python3-pip is already installed at the requested version (18.1-5)
python-pip is already installed at the requested version (18.1-5)
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.