I am getting ImportError: No module named '_gdbm' error whenever the command I enter is not valid

work@suresh-Lenovo-B50-80:~$ sadfsdf

Traceback (most recent call last):
  File "/usr/lib/python3.5/dbm/gnu.py", line 4, in <module>
    from _gdbm import *
ImportError: No module named '_gdbm'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 7, in <module>
    import dbm.gnu as gdbm
  File "/usr/lib/python3.5/dbm/gnu.py", line 6, in <module>
    raise ImportError(str(msg) + ', please install the python3-gdbm package')
ImportError: No module named '_gdbm', please install the python3-gdbm package

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/command-not-found", line 27, in <module>
    from CommandNotFound.util import crash_guard
  File "/usr/lib/python3/dist-packages/CommandNotFound/__init__.py", line 3, in <module>
    from CommandNotFound.CommandNotFound import CommandNotFound
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 9, in <module>
    import gdbm
ImportError: No module named 'gdbm'
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
    from apport.report import Report
  File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>
    import apport.fileutils
  File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>
    from apport.packaging_impl import impl as packaging
  File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 20, in <module>
    import apt
  File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>
    import apt_pkg
ImportError: No module named 'apt_pkg'

Original exception was:
Traceback (most recent call last):
  File "/usr/lib/python3.5/dbm/gnu.py", line 4, in <module>
    from _gdbm import *
ImportError: No module named '_gdbm'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 7, in <module>
    import dbm.gnu as gdbm
  File "/usr/lib/python3.5/dbm/gnu.py", line 6, in <module>
    raise ImportError(str(msg) + ', please install the python3-gdbm package')
ImportError: No module named '_gdbm', please install the python3-gdbm package

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/command-not-found", line 27, in <module>
    from CommandNotFound.util import crash_guard
  File "/usr/lib/python3/dist-packages/CommandNotFound/__init__.py", line 3, in <module>
    from CommandNotFound.CommandNotFound import CommandNotFound
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 9, in <module>
    import gdbm
ImportError: No module named 'gdbm'
work@suresh-Lenovo-B50-80:~$