diff --git a/lib/bx/align/core.py b/lib/bx/align/core.py
index 21aa53c..5034976 100644
--- a/lib/bx/align/core.py
+++ b/lib/bx/align/core.py
@@ -312,9 +312,7 @@ def reverse_complement(self):
         if self.empty:
             text = None
         else:
-            comp = [ch for ch in self.text.translate(DNA_COMP)]
-            comp.reverse()
-            text = "".join(comp)
+            text = self.text.translate(DNA_COMP)[::-1]
         new = Component(self.src, start, self.size, strand, self._src_size, text)
         if self.empty:
             new.empty = True
@@ -386,7 +384,7 @@ def coord_to_col(self, pos):
         if pos < start or pos > end:
             raise ValueError("Range error: %d not in %d-%d" % (pos, start, end))
         if not self.index:
-            self.index = list()
+            self.index = []
             if self.strand == "-":
                 # nota bene: for - strand self.index[x] maps to one column
                 # higher than is actually associated with the position;  thus
diff --git a/lib/bx/align/lav.py b/lib/bx/align/lav.py
index 50e7d34..d3e4a7e 100644
--- a/lib/bx/align/lav.py
+++ b/lib/bx/align/lav.py
@@ -476,7 +476,7 @@ def write(self, alignment):
         self.block += 1
 
     def close(self):
-        keys = [key for key in self.blockHash]
+        keys = list(self.blockHash)
         keys = sort_keys_by_chrom(keys)
         for key in keys:
             (src1, strand1, src2, strand2) = key
diff --git a/lib/bx/align/score.py b/lib/bx/align/score.py
index 0aa1f9b..89897a1 100644
--- a/lib/bx/align/score.py
+++ b/lib/bx/align/score.py
@@ -33,9 +33,9 @@ def __init__(
         if gap2 is None:
             gap2 = gap1  # (scheme with gap1=gap2=None is legit)
         if isinstance(alphabet1, str):
-            alphabet1 = [ch for ch in alphabet1]
+            alphabet1 = list(alphabet1)
         if isinstance(alphabet2, str):
-            alphabet2 = [ch for ch in alphabet2]
+            alphabet2 = list(alphabet2)
         self.table = ones((text1_range, text2_range), typecode)
         self.table *= default
         self.gap_open = gap_open
@@ -143,7 +143,7 @@ def read_scoring_scheme(f, gap_open, gap_extend, gap1="-", gap2=None, **kwargs):
     if isinstance(f, str):
         f = open(f)
         close_it = True
-    ss = build_scoring_scheme("".join([line for line in f]), gap_open, gap_extend, gap1=gap1, gap2=gap2, **kwargs)
+    ss = build_scoring_scheme("".join(list(f)), gap_open, gap_extend, gap1=gap1, gap2=gap2, **kwargs)
     if close_it:
         f.close()
     return ss
diff --git a/lib/bx/align/sitemask/cpg.py b/lib/bx/align/sitemask/cpg.py
index 7b3be2e..a01d3eb 100644
--- a/lib/bx/align/sitemask/cpg.py
+++ b/lib/bx/align/sitemask/cpg.py
@@ -83,13 +83,13 @@ def __call__(self, block):
 
 
 def mask_columns(masklist, text, mask):
-    templist = list()
+    templist = []
     for position in masklist:
         if text[position] != "-":
             templist.append(position)
     templist.append(len(text))  # Add the end of the text
     # cut string
-    newtext = list()
+    newtext = []
     c = 0
     for position in templist:
         newtext.append(text[c:position])
diff --git a/lib/bx/bitset_builders.py b/lib/bx/bitset_builders.py
index d8657c1..16ebebb 100644
--- a/lib/bx/bitset_builders.py
+++ b/lib/bx/bitset_builders.py
@@ -28,7 +28,7 @@ def binned_bitsets_from_file(
     """
     last_chrom = None
     last_bitset = None
-    bitsets = dict()
+    bitsets = {}
     for line in f:
         if line.startswith("#") or line.isspace():
             continue
@@ -68,7 +68,7 @@ def binned_bitsets_from_bed_file(
     """
     last_chrom = None
     last_bitset = None
-    bitsets = dict()
+    bitsets = {}
     offset = 0
     for line in f:
         if line.startswith("#") or line.isspace():
@@ -108,7 +108,7 @@ def binned_bitsets_proximity(f, chrom_col=0, start_col=1, end_col=2, strand_col=
     """Read a file into a dictionary of bitsets"""
     last_chrom = None
     last_bitset = None
-    bitsets = dict()
+    bitsets = {}
     for line in f:
         if line.startswith("#"):
             continue
@@ -143,7 +143,7 @@ def binned_bitsets_from_list(list=[]):
     """Read a list into a dictionary of bitsets"""
     last_chrom = None
     last_bitset = None
-    bitsets = dict()
+    bitsets = {}
     for l in list:
         chrom = l[0]
         if chrom != last_chrom:
diff --git a/lib/bx/cookbook/argparse.py b/lib/bx/cookbook/argparse.py
index 849b938..4bb7999 100644
--- a/lib/bx/cookbook/argparse.py
+++ b/lib/bx/cookbook/argparse.py
@@ -304,15 +304,15 @@ def _format_usage(self, usage, actions, groups, prefix):
 
         # if usage is specified, use that
         if usage is not None:
-            usage = usage % dict(prog=self._prog)
+            usage = usage % {"prog": self._prog}
 
         # if no optionals or positionals are available, usage is just prog
         elif usage is None and not actions:
-            usage = "%(prog)s" % dict(prog=self._prog)
+            usage = "%(prog)s" % {"prog": self._prog}
 
         # if optionals and positionals are available, calculate usage
         elif usage is None:
-            prog = "%(prog)s" % dict(prog=self._prog)
+            prog = "%(prog)s" % {"prog": self._prog}
 
             # split optionals from positionals
             optionals = []
@@ -486,7 +486,7 @@ def _format_actions_usage(self, actions, groups):
 
     def _format_text(self, text):
         if "%(prog)" in text:
-            text = text % dict(prog=self._prog)
+            text = text % {"prog": self._prog}
         text_width = self._width - self._current_indent
         indent = " " * self._current_indent
         return self._fill_text(text, text_width, indent) + "\n\n"
@@ -704,7 +704,7 @@ def __str__(self):
             format = "%(message)s"
         else:
             format = "argument %(argument_name)s: %(message)s"
-        return format % dict(message=self.message, argument_name=self.argument_name)
+        return format % {"message": self.message, "argument_name": self.argument_name}
 
 
 class ArgumentTypeError(Exception):
diff --git a/lib/bx/cookbook/doc_optparse.py b/lib/bx/cookbook/doc_optparse.py
index 81f9afc..af8ecc8 100644
--- a/lib/bx/cookbook/doc_optparse.py
+++ b/lib/bx/cookbook/doc_optparse.py
@@ -85,7 +85,7 @@ def parse(docstring, arglist=None):
                     action = "store"
                     k = k.split("=")[0]
                 opt_strings.append(k)
-            p.add_option(*opt_strings, **dict(action=action, help=help.strip()))
+            p.add_option(*opt_strings, **{"action": action, "help": help.strip()})
     except (IndexError, ValueError):
         raise ParsingError("Cannot parse the option string correctly")
     return p.parse_args(arglist)
diff --git a/lib/bx/filter.py b/lib/bx/filter.py
index b130271..f71b34c 100644
--- a/lib/bx/filter.py
+++ b/lib/bx/filter.py
@@ -28,7 +28,7 @@ def __call__(self, block):
 
 class Pipeline(Filter):
     def __init__(self, **kwargs):
-        self.pipeline = list()
+        self.pipeline = []
 
     def __call__(self, block):
         for function in self.pipeline:
diff --git a/lib/bx/interval_index_file.py b/lib/bx/interval_index_file.py
index 03a1cc8..fb5372c 100644
--- a/lib/bx/interval_index_file.py
+++ b/lib/bx/interval_index_file.py
@@ -178,7 +178,7 @@ def new_indexed_access(self, data_filename, index_filename=None, keep_open=False
         return self.indexed_access_class(data_filename, index_filename, keep_open, **kwargs)
 
     def get(self, src, start, end):
-        return [block for block in self.get_as_iterator(src, start, end)]
+        return list(self.get_as_iterator(src, start, end))
 
     def get_as_iterator(self, src, start, end):
         for block, _index, _offset in self.get_as_iterator_with_index_and_offset(src, start, end):
@@ -257,7 +257,7 @@ def open_data(self):
             return f
 
     def get(self, src, start, end):
-        return [val for val in self.get_as_iterator(src, start, end)]
+        return list(self.get_as_iterator(src, start, end))
 
     def get_as_iterator(self, src, start, end):
         for val, _index, _offset in self.get_as_iterator_with_index_and_offset(src, start, end):
@@ -287,7 +287,7 @@ class Indexes:
     """A set of indexes, each identified by a unique name"""
 
     def __init__(self, filename=None):
-        self.indexes = dict()
+        self.indexes = {}
         if filename is not None:
             self.open(filename)
 
@@ -312,7 +312,7 @@ def find(self, name, start, end):
 
     def open(self, filename):
         self.filename = filename
-        self.offsets = dict()  # (will map key to (offset,value_size))
+        self.offsets = {}  # (will map key to (offset,value_size))
         with open(filename, "rb") as f:
             magic, version, length = read_packed(f, ">3I")
             if magic != MAGIC:
diff --git a/lib/bx/intervals/cluster_tests.py b/lib/bx/intervals/cluster_tests.py
index 1fa0957..d973a1c 100644
--- a/lib/bx/intervals/cluster_tests.py
+++ b/lib/bx/intervals/cluster_tests.py
@@ -49,7 +49,7 @@ def test_large_sorted(self):
         pairs = [(2 * i + 1, 2 * i + 2) for i in range(upto)]
         self.insertpairs(pairs)
         self.tree.insert(0, upto * 3, upto)
-        self.assertEqual([(0, upto * 3, [x for x in range(upto + 1)])], self.tree.getregions())
+        self.assertEqual([(0, upto * 3, list(range(upto + 1)))], self.tree.getregions())
 
     def test_minregions(self):
         self.tree = ClusterTree(0, 2)
@@ -92,7 +92,7 @@ def test_larger(self):
         ]
         self.insertpairs(pairs)
 
-        self.assertEqual([(1, 20, [x for x in range(14)]), (21, 22, [14])], self.tree.getregions())
+        self.assertEqual([(1, 20, list(range(14))), (21, 22, [14])], self.tree.getregions())
 
     def test_another(self):
         pairs = [
@@ -116,7 +116,7 @@ def test_another(self):
         for s, e, i in pairs:
             self.tree.insert(s, e, i)
 
-        self.assertEqual([(1, 20, [x for x in range(14)]), (21, 22, [14])], self.tree.getregions())
+        self.assertEqual([(1, 20, list(range(14))), (21, 22, [14])], self.tree.getregions())
 
     def test_none(self):
         pairs = []
diff --git a/lib/bx/intervals/intersection_tests.py b/lib/bx/intervals/intersection_tests.py
index 45febc1..c719661 100644
--- a/lib/bx/intervals/intersection_tests.py
+++ b/lib/bx/intervals/intersection_tests.py
@@ -160,13 +160,13 @@ def setUp(self):
         iv = IntervalTree()
         n = 0
         for i in range(1, 1000, 80):
-            iv.insert(i, i + 10, dict(value=i * i))
+            iv.insert(i, i + 10, {"value": i * i})
             # add is synonym for insert.
-            iv.add(i + 20, i + 30, dict(astr=str(i * i)))
+            iv.add(i + 20, i + 30, {"astr": str(i * i)})
 
             # or insert/add an interval object with start, end attrs.
-            iv.insert_interval(Interval(i + 40, i + 50, value=dict(astr=str(i * i))))
-            iv.add_interval(Interval(i + 60, i + 70, value=dict(astr=str(i * i))))
+            iv.insert_interval(Interval(i + 40, i + 50, value={"astr": str(i * i)}))
+            iv.add_interval(Interval(i + 60, i + 70, value={"astr": str(i * i)}))
 
             n += 4
         self.intervals = self.iv = iv
diff --git a/lib/bx/intervals/io.py b/lib/bx/intervals/io.py
index e41f6a9..08eca9e 100644
--- a/lib/bx/intervals/io.py
+++ b/lib/bx/intervals/io.py
@@ -194,7 +194,7 @@ def binned_bitsets(self, upstream_pad=0, downstream_pad=0, lens=None):
             lens = {}
         last_chrom = None
         last_bitset = None
-        bitsets = dict()
+        bitsets = {}
         for interval in self:
             if isinstance(interval, GenomicInterval):
                 chrom = interval[self.chrom_col]
diff --git a/lib/bx/intervals/operations/find_clusters.py b/lib/bx/intervals/operations/find_clusters.py
index 2940646..fb9fb5c 100644
--- a/lib/bx/intervals/operations/find_clusters.py
+++ b/lib/bx/intervals/operations/find_clusters.py
@@ -18,8 +18,8 @@
 
 
 def find_clusters(reader, mincols=1, minregions=2):
-    extra = dict()
-    chroms = dict()
+    extra = {}
+    chroms = {}
     linenum = -1
     for interval in reader:
         linenum += 1
diff --git a/lib/bx/intervals/operations/join.py b/lib/bx/intervals/operations/join.py
index 2112d90..62a0956 100644
--- a/lib/bx/intervals/operations/join.py
+++ b/lib/bx/intervals/operations/join.py
@@ -68,7 +68,7 @@ def report_unvisited(node, results):
         results = []
         rightTree.traverse(lambda x: report_unvisited(x, results))
         for item in results:
-            outfields = list()
+            outfields = []
             for x in range(leftlen):
                 outfields.append(".")
             outfields.extend(item.other)
diff --git a/lib/bx/misc/seekbzip2.py b/lib/bx/misc/seekbzip2.py
index 03372e0..c654841 100644
--- a/lib/bx/misc/seekbzip2.py
+++ b/lib/bx/misc/seekbzip2.py
@@ -149,7 +149,7 @@ def readable(self):
         return True
 
     def readlines(self, sizehint=-1):
-        return [ln for ln in self]
+        return list(self)
 
     def seekable(self):
         return True
diff --git a/lib/bx/pwm/position_weight_matrix.py b/lib/bx/pwm/position_weight_matrix.py
index b661f1f..d8c5f1e 100755
--- a/lib/bx/pwm/position_weight_matrix.py
+++ b/lib/bx/pwm/position_weight_matrix.py
@@ -228,7 +228,7 @@ def __init__(self, id, rows, alphabet, background=None, score_correction=True):
 
         # scale counts to integers
         for i in range(len(rows)):
-            hashRows.append(dict())
+            hashRows.append({})
             for x, sym in enumerate(alphabet):
                 (w, s) = rows[i][x]
                 hashRows[i][sym] = w * scale / s
diff --git a/lib/bx/pwm/pwm_tests.py b/lib/bx/pwm/pwm_tests.py
index b2b7dfd..db143c1 100644
--- a/lib/bx/pwm/pwm_tests.py
+++ b/lib/bx/pwm/pwm_tests.py
@@ -66,18 +66,11 @@
 class PWMTestCase(unittest.TestCase):
     def testReader(self):
         # test basic format: i.e. for jaspar
-        wms = [
-            wm for wm in pwm.Reader(StringIO(basicPwm), format="basic", background=background, score_correction=False)
-        ]
+        wms = list(pwm.Reader(StringIO(basicPwm), format="basic", background=background, score_correction=False))
         assert len(wms) == 1
 
         # test transfac format
-        wms = [
-            wm
-            for wm in pwm.Reader(
-                StringIO(transfacPwm), format="transfac", background=background, score_correction=False
-            )
-        ]
+        wms = list(pwm.Reader(StringIO(transfacPwm), format="transfac", background=background, score_correction=False))
         assert len(wms) == 1
 
         wm = wms[0]
@@ -87,7 +80,7 @@ def testReader(self):
 
         qdSeq = []
         for ix, nt in enumerate(dSeq):
-            qdSeq.append(dict())
+            qdSeq.append({})
             qdSeq[ix][nt] = 1.0
         qScores = wm.score_seq(qdSeq)
         assert len(qScores) == 2
diff --git a/lib/bx/seq/seq.py b/lib/bx/seq/seq.py
index 81cc92e..16cc047 100644
--- a/lib/bx/seq/seq.py
+++ b/lib/bx/seq/seq.py
@@ -106,9 +106,7 @@ def raw_fetch(self, start, length):
         return self.text[start : start + length]
 
     def reverse_complement(self, text):
-        comp = [ch for ch in text.translate(DNA_COMP)]
-        comp.reverse()
-        return "".join(comp)
+        return text.translate(DNA_COMP)[::-1]
 
 
 class SeqReader:
diff --git a/lib/bx/seq/twobit.py b/lib/bx/seq/twobit.py
index 36e0571..5f69a6d 100644
--- a/lib/bx/seq/twobit.py
+++ b/lib/bx/seq/twobit.py
@@ -84,7 +84,7 @@ def __init__(self, file: BinaryIO, do_mask: bool = True):
         # Header contains some reserved space
         self.reserved = self.read("L")
         # Read index of sequence names to offsets
-        index: Dict[str, TwoBitSequence] = dict()
+        index: Dict[str, TwoBitSequence] = {}
         for _ in range(self.seq_count):
             name = self.read_p_string()
             offset = self.read("L")
diff --git a/lib/bx_extras/pyparsing.py b/lib/bx_extras/pyparsing.py
index ae1b882..0a33d14 100644
--- a/lib/bx_extras/pyparsing.py
+++ b/lib/bx_extras/pyparsing.py
@@ -318,7 +318,7 @@ def __init__(self, toklist, name=None, asList=True, modal=True):
                 self.__toklist = toklist[:]
             else:
                 self.__toklist = [toklist]
-            self.__tokdict = dict()
+            self.__tokdict = {}
 
         # this line is related to debugging the asXML bug
         # ~ asList = False
@@ -355,13 +355,13 @@ def __getitem__(self, i):
 
     def __setitem__(self, k, v):
         if isinstance(v, _ParseResultsWithOffset):
-            self.__tokdict[k] = self.__tokdict.get(k, list()) + [v]
+            self.__tokdict[k] = self.__tokdict.get(k, []) + [v]
             sub = v[0]
         elif isinstance(k, int):
             self.__toklist[k] = v
             sub = v
         else:
-            self.__tokdict[k] = self.__tokdict.get(k, list()) + [_ParseResultsWithOffset(v, 0)]
+            self.__tokdict[k] = self.__tokdict.get(k, []) + [_ParseResultsWithOffset(v, 0)]
             sub = v
         if isinstance(sub, ParseResults):
             sub.__parent = wkref(self)
@@ -698,7 +698,7 @@ def setDefaultWhitespaceChars(chars):
     setDefaultWhitespaceChars = staticmethod(setDefaultWhitespaceChars)
 
     def __init__(self, savelist=False):
-        self.parseAction = list()
+        self.parseAction = []
         self.failAction = None
         # ~ self.name = "<unknown>"  # don't define self.name, let subclasses try/except upcall
         self.strRepr = None
@@ -709,7 +709,7 @@ def __init__(self, savelist=False):
         self.copyDefaultWhiteChars = True
         self.mayReturnEmpty = False  # used when checking for left-recursion
         self.keepTabs = False
-        self.ignoreExprs = list()
+        self.ignoreExprs = []
         self.debug = False
         self.streamlined = False
         self.mayIndexError = True  # used to optimize exception handling for subclasses that don't advance parse index
@@ -2585,7 +2585,7 @@ def parseImpl(self, instring, loc, doActions=True):
             raise ParseException(instring, loc, "Missing one or more required elements (%s)" % missing)
 
         # add any unmatched Optionals, in case they have default values defined
-        matchOrder += list(e for e in self.exprs if isinstance(e, Optional) and e.expr in tmpOpt)
+        matchOrder += [e for e in self.exprs if isinstance(e, Optional) and e.expr in tmpOpt]
 
         resultlist = []
         for e in matchOrder:
@@ -3531,7 +3531,7 @@ def withAttribute(*args, **attrDict):
         attrs = args[:]
     else:
         attrs = attrDict.items()
-    attrs = [(k, v) for k, v in attrs]
+    attrs = list(attrs)
 
     def pa(s, l, tokens):
         for attrName, attrValue in attrs:
diff --git a/pyproject.toml b/pyproject.toml
index 8c4a108..48a27d9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -84,7 +84,7 @@ target-version = "py38"
 # flake8-implicit-str-concat (ISC), NumPy-specific rules (NPY)
 # and pyupgrade (UP)
 #select = ["E", "F", "B", "C4", "G", "ISC", "NPY", "UP"]
-select = ["E", "F", "G", "ISC", "NPY"]
+select = ["E", "F", "C4", "G", "ISC", "NPY"]
 # Exceptions:
 # B9 flake8-bugbear opinionated warnings
 # E501 is line length (delegated to black)
diff --git a/script_tests/base/__init__.py b/script_tests/base/__init__.py
index ad42a6a..60e47cf 100644
--- a/script_tests/base/__init__.py
+++ b/script_tests/base/__init__.py
@@ -39,8 +39,8 @@ class BaseScriptTest:
 
     def test_script(self):
         # Accumulate parameters
-        input_files = dict()
-        output_files = dict()
+        input_files = {}
+        output_files = {}
         out_dir = None
         stdin = stdout = stderr = None
         for key in dir(self):
@@ -60,9 +60,9 @@ def test_script(self):
                 out_dir = getattr(self, key)
                 assert os.path.isdir(out_dir)
         # Build the command line
-        input_fnames = dict()
-        output_fnames = dict()
-        all_fnames = dict()
+        input_fnames = {}
+        output_fnames = {}
+        all_fnames = {}
         for key, value in input_files.items():
             input_fnames[key] = value.filename
             all_fnames[key] = input_fnames[key]
diff --git a/scripts/aggregate_scores_in_intervals.py b/scripts/aggregate_scores_in_intervals.py
index d5eabb0..2f7f0f4 100755
--- a/scripts/aggregate_scores_in_intervals.py
+++ b/scripts/aggregate_scores_in_intervals.py
@@ -36,7 +36,7 @@ class FileBinnedArrayDir(Mapping):
 
     def __init__(self, dir):
         self.dir = dir
-        self.cache = dict()
+        self.cache = {}
 
     def __getitem__(self, key):
         value = None
@@ -63,7 +63,7 @@ def load_scores_wiggle(fname):
     Read a wiggle file and return a dict of BinnedArray objects keyed
     by chromosome.
     """
-    scores_by_chrom = dict()
+    scores_by_chrom = {}
     for chrom, pos, val in bx.wiggle.Reader(misc.open_compressed(fname)):
         if chrom not in scores_by_chrom:
             scores_by_chrom[chrom] = BinnedArray()
diff --git a/scripts/bed_complement.py b/scripts/bed_complement.py
index 3ae3030..b9607ca 100755
--- a/scripts/bed_complement.py
+++ b/scripts/bed_complement.py
@@ -14,7 +14,7 @@
 
 def read_len(f):
     """Read a 'LEN' file and return a mapping from chromosome to length"""
-    mapping = dict()
+    mapping = {}
     for line in f:
         fields = line.split()
         mapping[fields[0]] = int(fields[1])
diff --git a/scripts/bed_coverage_by_interval.py b/scripts/bed_coverage_by_interval.py
index 13f89ff..fe8c269 100755
--- a/scripts/bed_coverage_by_interval.py
+++ b/scripts/bed_coverage_by_interval.py
@@ -25,7 +25,7 @@ def clone(bits):
 if len(sys.argv) > 3:
     mask_fname = sys.argv[3]
     mask = binned_bitsets_from_file(open(mask_fname))
-    new_bitsets = dict()
+    new_bitsets = {}
     for key in bitsets:
         if key in mask:
             b = clone(mask[key])
diff --git a/scripts/bed_diff_basewise_summary.py b/scripts/bed_diff_basewise_summary.py
index 0b33d02..f8d91ec 100755
--- a/scripts/bed_diff_basewise_summary.py
+++ b/scripts/bed_diff_basewise_summary.py
@@ -30,7 +30,7 @@ def coverage(bitsets):
 bits1_covered = coverage(bits1)
 bits2_covered = coverage(bits2)
 
-bitsets = dict()
+bitsets = {}
 
 for key in bits1:
     if key in bits2:
diff --git a/scripts/bed_intersect_basewise.py b/scripts/bed_intersect_basewise.py
index 42045eb..7a78f0f 100755
--- a/scripts/bed_intersect_basewise.py
+++ b/scripts/bed_intersect_basewise.py
@@ -20,7 +20,7 @@
 bits1 = binned_bitsets_from_file(open(in_fname))
 bits2 = binned_bitsets_from_file(open(in2_fname))
 
-bitsets = dict()
+bitsets = {}
 
 for key in bits1:
     if key in bits2:
diff --git a/scripts/get_scores_in_intervals.py b/scripts/get_scores_in_intervals.py
index 60d1081..54c0919 100755
--- a/scripts/get_scores_in_intervals.py
+++ b/scripts/get_scores_in_intervals.py
@@ -18,7 +18,7 @@
 
 
 def read_scores(f):
-    scores_by_chrom = dict()
+    scores_by_chrom = {}
     for chrom, pos, val in bx.wiggle.Reader(f):
         if chrom not in scores_by_chrom:
             scores_by_chrom[chrom] = BinnedArray()
diff --git a/scripts/mMK_bitset.py b/scripts/mMK_bitset.py
index 00a312a..671cc1b 100644
--- a/scripts/mMK_bitset.py
+++ b/scripts/mMK_bitset.py
@@ -33,8 +33,8 @@ def main():
     neutral_bitsets = binned_bitsets_from_file(open(neutral_filename))
 
     # Generate divergence bitset from maf file
-    AR_div_bitsets = dict()
-    chr_lens = dict()
+    AR_div_bitsets = {}
+    chr_lens = {}
     reader = bx.align.maf.Reader(open(maf_filename))
 
     for block in reader:
@@ -69,12 +69,12 @@ def main():
             pos += 1
 
     # Copy div and snp bitsets
-    nonAR_snp_bitsets = dict()
+    nonAR_snp_bitsets = {}
     for chr in AR_snp_bitsets:
         nonAR_snp_bitsets[chr] = bx.bitset.BinnedBitSet()
         nonAR_snp_bitsets[chr].ior(AR_snp_bitsets[chr])
 
-    nonAR_div_bitsets = dict()
+    nonAR_div_bitsets = {}
     for chr in AR_div_bitsets:
         nonAR_div_bitsets[chr] = bx.bitset.BinnedBitSet()
         nonAR_div_bitsets[chr].ior(AR_div_bitsets[chr])
diff --git a/scripts/maf_covered_regions.py b/scripts/maf_covered_regions.py
index 0099e88..ce23526 100755
--- a/scripts/maf_covered_regions.py
+++ b/scripts/maf_covered_regions.py
@@ -35,7 +35,7 @@ def block_pid(comp1, comp2):
 def main():
     out_prefix = sys.argv[1]
     print(out_prefix)
-    out_files = dict()
+    out_files = {}
     for block in bx.align.maf.Reader(sys.stdin):
         ref_comp = block.components[0]
         ref_chrom = ref_comp.src.split(".")[1]
diff --git a/scripts/maf_extract_chrom_ranges.py b/scripts/maf_extract_chrom_ranges.py
index 07c252f..58b5566 100755
--- a/scripts/maf_extract_chrom_ranges.py
+++ b/scripts/maf_extract_chrom_ranges.py
@@ -46,7 +46,7 @@ def __main__():
 
     # Load Intervals
 
-    intersecters = dict()
+    intersecters = {}
     for line in open(range_filename):
         fields = line.split()
         src = prefix + fields[0]
diff --git a/scripts/mask_quality.py b/scripts/mask_quality.py
index e97fa58..66df4cc 100644
--- a/scripts/mask_quality.py
+++ b/scripts/mask_quality.py
@@ -50,7 +50,7 @@ def main():
     for entry in specieslist:
         fields = entry.split(",")
         lenstream = fileinput.FileInput(fields[1])
-        lendict = dict()
+        lendict = {}
         for line in lenstream:
             region = line.split()
             lendict[region[0]] = int(region[1])
diff --git a/scripts/table_add_column.py b/scripts/table_add_column.py
index f845963..2d096ea 100755
--- a/scripts/table_add_column.py
+++ b/scripts/table_add_column.py
@@ -38,7 +38,7 @@ def __main__():
             if keep_comments:
                 print(element)
         else:
-            val = eval(expr, dict(row=element))
+            val = eval(expr, {"row": element})
             print(str(element) + "\t" + str(val))
 
 
diff --git a/scripts/table_filter.py b/scripts/table_filter.py
index 3138404..16a872b 100755
--- a/scripts/table_filter.py
+++ b/scripts/table_filter.py
@@ -61,7 +61,7 @@ def __main__():
             if keep_comments:
                 print(element)
         else:
-            if expr is None or bool(eval(expr, dict(row=element))):
+            if expr is None or bool(eval(expr, {"row": element})):
                 if cols:
                     print("\t".join(element[c] for c in cols))
                 else:
diff --git a/setup.py b/setup.py
index 0d2d152..72d8b61 100644
--- a/setup.py
+++ b/setup.py
@@ -10,7 +10,7 @@
 
 
 def main():
-    metadata = dict(scripts=glob("scripts/*.py"), cmdclass=command_classes)
+    metadata = {"scripts": glob("scripts/*.py"), "cmdclass": command_classes}
 
     if len(sys.argv) >= 2 and (
         "--help" in sys.argv[1:] or sys.argv[1] in ("--help-commands", "egg_info", "--version", "clean")