pylint error

No config file found, using default configuration
************* Module hw01
C:  1, 0: Missing module docstring (missing-docstring)
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.5/bin/pylint", line 11, in <module>
    sys.exit(run_pylint())
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/__init__.py", line 23, in run_pylint
    Run(sys.argv[1:])
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/lint.py", line 1332, in __init__
    linter.check(args)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/lint.py", line 747, in check
    self._do_check(files_or_modules)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/lint.py", line 869, in _do_check
    self.check_astroid_module(ast_node, walker, rawcheckers, tokencheckers)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/lint.py", line 946, in check_astroid_module
    walker.walk(ast_node)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/utils.py", line 874, in walk
    self.walk(child)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/utils.py", line 871, in walk
    cb(astroid)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/checkers/imports.py", line 276, in visit_from
    importedmodnode = self.get_imported_module(node, basename)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pylint/checkers/imports.py", line 288, in get_imported_module
    return importnode.do_import_module(modname)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/mixins.py", line 107, in do_import_module
    return mymodule.import_module(modname, level=level)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/scoped_nodes.py", line 425, in import_module
    return MANAGER.ast_from_module_name(absmodname)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/manager.py", line 160, in ast_from_module_name
    return self.ast_from_file(filepath, modname, fallback=False)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/manager.py", line 112, in ast_from_file
    return AstroidBuilder(self).file_build(filepath, modname)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/builder.py", line 134, in file_build
    module = self._data_build(data, modname, path)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/builder.py", line 177, in _data_build
    module = rebuilder.visit_module(node, modname, node_file, package)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 148, in visit_module
    newnode.body = [self.visit(child, newnode) for child in node.body]
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 148, in <listcomp>
    newnode.body = [self.visit(child, newnode) for child in node.body]
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 161, in visit
    return self._transform(visit_method(node, parent))
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 502, in visit_function
    newnode.body = [self.visit(child, newnode) for child in node.body]
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 502, in <listcomp>
    newnode.body = [self.visit(child, newnode) for child in node.body]
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 161, in visit
    return self._transform(visit_method(node, parent))
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 706, in visit_return
    newnode.value = self.visit(node.value, newnode)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 161, in visit
    return self._transform(visit_method(node, parent))
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/astroid/rebuilder.py", line 308, in visit_binop
    newnode.op = _BIN_OP_CLASSES[node.op.__class__]
KeyError: <class '_ast.MatMult'>