# Buggy code
def __setitem__(self, key, value):
    if hashable(key) and key not in self.columns:
        # Handle new column case first
        if isinstance(value, Series):
            if len(self.columns) == 0:
                self._query_compiler = value._query_compiler.copy()
            else:
                self._create_or_update_from_compiler(
                    self._query_compiler.concat(
                        1,
                        value._query_compiler,
                        join="left",
                    ),
                    inplace=True,
                )
            # Now that the data is appended, we need to update the column name for
            # that column to `key`, otherwise the name could be incorrect. Drop the
            # last column name from the list (the appended value's name and append
            # the new name.
            self.columns = self.columns[:-1].append(pandas.Index([key]))
            return
        elif isinstance(value, (pandas.DataFrame, DataFrame)) and value.shape[1] != 1:
            raise ValueError(
                "Wrong number of items passed %i, placement implies 1" % value.shape[1]
            )
        elif isinstance(value, np.ndarray) and len(value.shape) > 1:
            if value.shape[1] == 1:
                # Transform into columnar table and take first column
                value = value.copy().T[0]
            else:
                raise ValueError(
                    "Wrong number of items passed %i, placement implies 1"
                    % value.shape[1]
                )

        # Do new column assignment after error checks and possible value modifications
        self.insert(loc=len(self.columns), column=key, value=value)
        return

    if not isinstance(key, str):
        if isinstance(key, DataFrame) or isinstance(key, np.ndarray):
            if isinstance(key, np.ndarray):
                if key.shape != self.shape:
                    raise ValueError("Array must be same shape as DataFrame")
                key = DataFrame(key, columns=self.columns)
            return self.mask(key, value, inplace=True)

        def setitem_without_string_columns(df):
            # Arrow makes memory-mapped objects immutable, so copy will allow them
            # to be mutable again.
            df = df.copy(True)
            df[key] = value
            return df

        return self._update_inplace(
            self._default_to_pandas(setitem_without_string_columns)._query_compiler
        )
    if is_list_like(value):
        if isinstance(value, (pandas.DataFrame, DataFrame)):
            value = value[value.columns[0]].values
        elif isinstance(value, np.ndarray):
            assert len(value.shape) < 3, (
                "Shape of new values must be compatible with manager shape"
            )
            value = value.T.reshape(-1)
            if len(self) > 0:
                value = value[: len(self)]
        if not isinstance(value, Series):
            value = list(value)

    if not self._query_compiler.lazy_execution and len(self.index) == 0:
        new_self = DataFrame({key: value}, columns=self.columns)
        self._update_inplace(new_self._query_compiler)
    else:
        if isinstance(value, Series):
            value = value._query_compiler
        self._update_inplace(self._query_compiler.setitem(0, key, value))


# Traceback (TypeError)
Traceback (most recent call last):
File "test_outer.py", line 13, in <module>
md_df["b"] = pd.Series(np.zeros(len(md_df))) # TypeError
File "/localdisk/dchigare/repos/modin_bp/modin/pandas/dataframe.py", line 1978, in __setitem__
join="left",
File "/localdisk/dchigare/repos/modin_bp/modin/backends/pandas/query_compiler.py", line 303, in concat
new_modin_frame = self._modin_frame._concat(axis, other_modin_frame, join, sort)
File "/localdisk/dchigare/repos/modin_bp/modin/engines/base/frame/data.py", line 1850, in _concat
axis ^ 1, others, how, sort, force_repartition=True
File "/localdisk/dchigare/repos/modin_bp/modin/engines/base/frame/data.py", line 1701, in _copartition
joined_index = self._join_index_objects(axis, index_other_obj, how, sort)
File "/localdisk/dchigare/repos/modin_bp/modin/engines/base/frame/data.py", line 980, in _join_index_objects
joined_obj = merge_index(joined_obj, obj)
File "/localdisk/dchigare/repos/modin_bp/modin/engines/base/frame/data.py", line 974, in merge_index
return obj1.join(obj2, how=how, sort=sort)
File "/localdisk/dchigare/miniconda3/envs/modin_tests/lib/python3.7/site-packages/pandas/core/indexes/datetimelike.py", line 893, in join
sort=sort,
File "/localdisk/dchigare/miniconda3/envs/modin_tests/lib/python3.7/site-packages/pandas/core/indexes/base.py", line 3483, in join
return this.join(other, how=how, return_indexers=return_indexers)
File "/localdisk/dchigare/miniconda3/envs/modin_tests/lib/python3.7/site-packages/pandas/core/indexes/base.py", line 3494, in join
other, how=how, return_indexers=return_indexers
File "/localdisk/dchigare/miniconda3/envs/modin_tests/lib/python3.7/site-packages/pandas/core/indexes/base.py", line 3815, in _join_monotonic
join_index, lidx, ridx = self._left_indexer(sv, ov)
File "/localdisk/dchigare/miniconda3/envs/modin_tests/lib/python3.7/site-packages/pandas/core/indexes/base.py", line 257, in _left_indexer
return libjoin.left_join_indexer(left, right)
File "pandas/_libs/join.pyx", line 357, in pandas._libs.join.left_join_indexer
TypeError: '<' not supported between instances of 'Timestamp' and 'int'

# Fixed code
def __setitem__(self, key, value):
    if hashable(key) and key not in self.columns:
        if isinstance(value, Series) and len(self.columns) == 0:
            self._query_compiler = value._query_compiler.copy()
            # Now that the data is appended, we need to update the column name for
            # that column to `key`, otherwise the name could be incorrect. Drop the
            # last column name from the list (the appended value's name and append
            # the new name.
            self.columns = self.columns[:-1].append(pandas.Index([key]))
            return
        elif isinstance(value, (pandas.DataFrame, DataFrame)) and value.shape[1] != 1:
            raise ValueError(
                "Wrong number of items passed %i, placement implies 1" % value.shape[1]
            )
        elif isinstance(value, np.ndarray) and len(value.shape) > 1:
            if value.shape[1] == 1:
                # Transform into columnar table and take first column
                value = value.copy().T[0]
            else:
                raise ValueError(
                    "Wrong number of items passed %i, placement implies 1"
                    % value.shape[1]
                )

        # Do new column assignment after error checks and possible value modifications
        self.insert(loc=len(self.columns), column=key, value=value)
        return

    if not isinstance(key, str):
        if isinstance(key, DataFrame) or isinstance(key, np.ndarray):
            if isinstance(key, np.ndarray):
                if key.shape != self.shape:
                    raise ValueError("Array must be same shape as DataFrame")
                key = DataFrame(key, columns=self.columns)
            return self.mask(key, value, inplace=True)

        def setitem_without_string_columns(df):
            # Arrow makes memory-mapped objects immutable, so copy will allow them
            # to be mutable again.
            df = df.copy(True)
            df[key] = value
            return df

        return self._update_inplace(
            self._default_to_pandas(setitem_without_string_columns)._query_compiler
        )
    if is_list_like(value):
        if isinstance(value, (pandas.DataFrame, DataFrame)):
            value = value[value.columns[0]].values
        elif isinstance(value, np.ndarray):
            assert len(value.shape) < 3, (
                "Shape of new values must be compatible with manager shape"
            )
            value = value.T.reshape(-1)
            if len(self) > 0:
                value = value[: len(self)]
        if not isinstance(value, Series):
            value = list(value)

    if not self._query_compiler.lazy_execution and len(self.index) == 0:
        new_self = DataFrame({key: value}, columns=self.columns)
        self._update_inplace(new_self._query_compiler)
    else:
        if isinstance(value, Series):
            value = value._query_compiler
        self._update_inplace(self._query_compiler.setitem(0, key, value))