diff --git a/nixio/block.py b/nixio/block.py
index 622f7b04..081f89ee 100644
--- a/nixio/block.py
+++ b/nixio/block.py
@@ -337,7 +337,7 @@ def create_data_frame(self, name="", type_="", col_dict=None,
             else:  # if col_names is None
                 if data is not None and type(data[0]) == np.void:
                     col_dtype = data[0].dtype
-                    for i, dt in enumerate(col_dtype.fields.values()):
+                    for dt in col_dtype.fields.values():
                         cn = list(col_dtype.fields.keys())
                         raw_dt = col_dtype.fields.values()
                         raw_dt = list(raw_dt)
diff --git a/nixio/data_array.py b/nixio/data_array.py
index 5aa56398..5b54752a 100644
--- a/nixio/data_array.py
+++ b/nixio/data_array.py
@@ -20,7 +20,7 @@
 from . import util
 from .compression import Compression
 
-from .exceptions import InvalidUnit, IncompatibleDimensions
+from .exceptions import IncompatibleDimensions
 from .section import Section
 
 
diff --git a/nixio/data_frame.py b/nixio/data_frame.py
index a4ce238e..9bb9cb74 100644
--- a/nixio/data_frame.py
+++ b/nixio/data_frame.py
@@ -185,7 +185,7 @@ def write_rows(self, rows, index):
             self._write_data(rows, sl=index)
         else:
             cr_list = []
-            for i, cr in enumerate(rows):
+            for cr in rows:
                 cr_list.append(tuple(cr))
             self._write_data(cr_list, sl=index)
 
diff --git a/nixio/file.py b/nixio/file.py
index a2985549..494e5a1b 100644
--- a/nixio/file.py
+++ b/nixio/file.py
@@ -46,8 +46,8 @@ def can_read(nixfile):
     filever = nixfile.version
     if len(filever) != 3:
         raise RuntimeError("Invalid version specified in file.")
-    vx, vy, vz = HDF_FF_VERSION
-    fx, fy, fz = filever
+    vx, vy, _ = HDF_FF_VERSION
+    fx, fy, _ = filever
     if vx == fx and vy >= fy:
         return True
     else:
diff --git a/nixio/section.py b/nixio/section.py
index d3a14ab5..ce5f1295 100644
--- a/nixio/section.py
+++ b/nixio/section.py
@@ -469,7 +469,7 @@ def __setitem__(self, key, data):
             prop.values = data
 
     def __iter__(self):
-        for name, item in self.items():
+        for _, item in self.items():
             yield item
 
     def items(self):
diff --git a/nixio/test/test_multi_tag.py b/nixio/test/test_multi_tag.py
index 628e8894..beb491f1 100644
--- a/nixio/test/test_multi_tag.py
+++ b/nixio/test/test_multi_tag.py
@@ -432,8 +432,8 @@ def test_multi_tag_tagged_data(self):
         assert (segdata.shape == (1, 5, 1))
 
         # retrieve all positions for all references
-        for ridx, ref in enumerate(mtag.references):
-            for pidx, p in enumerate(mtag.positions):
+        for ridx, _ in enumerate(mtag.references):
+            for pidx, _ in enumerate(mtag.positions):
                 mtag.tagged_data(pidx, ridx)
 
         wrong_pos = self.block.create_data_array("incorpos", "test",
@@ -462,7 +462,7 @@ def test_multi_tag_tagged_data_1d(self):
         onedmtag = self.block.create_multi_tag("2dmt", "mtag",
                                                positions=onedpos)
         onedmtag.references.append(oneddata)
-        for pidx, p in enumerate(onedmtag.positions):
+        for pidx, _ in enumerate(onedmtag.positions):
             onedmtag.tagged_data(pidx, 0)
 
     def test_multi_tag_feature_data(self):
diff --git a/nixio/test/xcompat/compile.py b/nixio/test/xcompat/compile.py
index 39dbd3f2..cce15099 100644
--- a/nixio/test/xcompat/compile.py
+++ b/nixio/test/xcompat/compile.py
@@ -41,7 +41,7 @@ def cc(filenames, dest,
         objnames = compiler.compile(filenames, output_dir=dest,
                                     extra_postargs=compile_args)
         for obj in objnames:
-            execname, ext = os.path.splitext(obj)
+            execname, _ = os.path.splitext(obj)
             compiler.link_executable(
                 [obj], execname, output_dir=dest,
                 target_lang="c++",
diff --git a/nixio/util/units.py b/nixio/util/units.py
index 536f9cdb..8a59d59b 100644
--- a/nixio/util/units.py
+++ b/nixio/util/units.py
@@ -137,8 +137,8 @@ def scalable(unit_a, unit_b):
     if not (is_si(unit_a) and is_si(unit_b)):
         return False
 
-    a_prefix, a_unit, a_power = split(unit_a)
-    b_prefix, b_unit, b_power = split(unit_b)
+    _, a_unit, a_power = split(unit_a)
+    _, b_unit, b_power = split(unit_b)
     if a_unit != b_unit or a_power != b_power:
         return False
 
@@ -163,8 +163,8 @@ def scaling(origin, destination):
             "nixio.util.scaling"
         )
 
-    org_prefix, org_unit, org_power = split(origin)
-    dest_prefix, dest_unit, dest_power = split(destination)
+    org_prefix, _, org_power = split(origin)
+    dest_prefix, _, dest_power = split(destination)
 
     if org_prefix == dest_prefix and org_power == dest_power:
         return scale