Fix some lgtm alerts (pandas-dev#16613)

pandas/core/dtypes/cast.py

@@ -668,7 +668,7 @@ def maybe_convert_objects(values, convert_dates=True, convert_numeric=True,
 
         if convert_timedeltas == 'coerce':
             from pandas.core.tools.timedeltas import to_timedelta
-            new_values = to_timedelta(values, coerce=True)
+            new_values = to_timedelta(values, errors='coerce')
 
             # if we are all nans then leave me alone
             if not isnull(new_values).all():

pandas/core/generic.py

@@ -4285,7 +4285,7 @@ def asof(self, where, subset=None):
                 raise ValueError("subset is not valid for Series")
         elif self.ndim > 2:
             raise NotImplementedError("asof is not implemented "
-                                      "for {type}".format(type(self)))
+                                      "for {type}".format(type=type(self)))
         else:
             if subset is None:
                 subset = self.columns
@@ -4980,7 +4980,7 @@ def last(self, offset):
 
         offset = to_offset(offset)
 
-        start_date = start = self.index[-1] - offset
+        start_date = self.index[-1] - offset
         start = self.index.searchsorted(start_date, side='right')
         return self.iloc[start:]
 
@@ -5303,8 +5303,8 @@ def _where(self, cond, other=np.nan, inplace=False, axis=None, level=None,
 
             # slice me out of the other
             else:
-                raise NotImplemented("cannot align with a higher dimensional "
-                                     "NDFrame")
+                raise NotImplementedError("cannot align with a higher "
+                                          "dimensional NDFrame")
 
         elif is_list_like(other):
 

pandas/core/indexes/interval.py

@@ -1053,11 +1053,11 @@ def interval_range(start=None, end=None, freq=None, periods=None,
         if periods is None or end is None:
             raise ValueError("must specify 2 of start, end, periods")
         start = end - periods * freq
-    elif end is None:
+    if end is None:
         if periods is None or start is None:
             raise ValueError("must specify 2 of start, end, periods")
         end = start + periods * freq
-    elif periods is None:
+    if periods is None:
         if start is None or end is None:
             raise ValueError("must specify 2 of start, end, periods")
         pass

pandas/core/internals.py

@@ -4645,7 +4645,6 @@ def _block2d_to_blocknd(values, placement, shape, labels, ref_items):
         pvalues = np.empty(panel_shape, dtype=dtype)
         pvalues.fill(fill_value)
 
-    values = values
     for i in range(len(placement)):
         pvalues[i].flat[mask] = values[:, i]
 
@@ -5154,8 +5153,6 @@ def dtype(self):
             return _get_dtype(maybe_promote(self.block.dtype,
                                             self.block.fill_value)[0])
 
-        return self._dtype
-
     @cache_readonly
     def is_null(self):
         if self.block is None:

pandas/core/sparse/array.py

@@ -125,7 +125,7 @@ def _sparse_array_op(left, right, op, name, series=False):
             name = name[1:]
 
         if name in ('and', 'or') and dtype == 'bool':
-            opname = 'sparse_{name}_uint8'.format(name=name, dtype=dtype)
+            opname = 'sparse_{name}_uint8'.format(name=name)
             # to make template simple, cast here
             left_sp_values = left.sp_values.view(np.uint8)
             right_sp_values = right.sp_values.view(np.uint8)

pandas/io/parsers.py

@@ -2211,7 +2211,7 @@ def _exclude_implicit_index(self, alldata):
     def get_chunk(self, size=None):
         if size is None:
             size = self.chunksize
-        return self.read(nrows=size)
+        return self.read(rows=size)
 
     def _convert_data(self, data):
         # apply converters

pandas/tseries/offsets.py

@@ -1596,7 +1596,6 @@ def apply(self, other):
             if otherDay != self.weekday:
                 other = other + timedelta((self.weekday - otherDay) % 7)
                 k = k - 1
-            other = other
             for i in range(k):
                 other = other + self._inc
         else: