diff --git a/mibuild/altera/quartus.py b/mibuild/altera/quartus.py
index 06f175285..02da446b8 100644
--- a/mibuild/altera/quartus.py
+++ b/mibuild/altera/quartus.py
@@ -50,10 +50,10 @@ def _build_files(device, sources, vincpaths, named_sc, named_pc, build_name):
         # Enforce use of SystemVerilog (Quartus does not support global parameters in Verilog)
         if language == "verilog":
             language = "systemverilog"
-        qsf_contents += "set_global_assignment -name "+language.upper()+"_FILE " + filename.replace("\\","/") + "\n"
+        qsf_contents += "set_global_assignment -name "+ language.upper() + "_FILE " + filename.replace("\\", "/") + "\n"
 
     for path in vincpaths:
-        qsf_contents += "set_global_assignment -name SEARCH_PATH " + path.replace("\\","/") + "\n"
+        qsf_contents += "set_global_assignment -name SEARCH_PATH " + path.replace("\\", "/") + "\n"
 
     qsf_contents += _build_qsf(named_sc, named_pc)
     qsf_contents += "set_global_assignment -name DEVICE " + device
diff --git a/mibuild/platforms/de0nano.py b/mibuild/platforms/de0nano.py
index eec8fd284..7e6d47b20 100644
--- a/mibuild/platforms/de0nano.py
+++ b/mibuild/platforms/de0nano.py
@@ -40,7 +40,7 @@ _io = [
         Subsignal("cas_n", Pins("L1")),
         Subsignal("we_n", Pins("C2")),
         Subsignal("dq", Pins("G2 G1 L8 K5 K2 J2 J1 R7 T4 T2 T3 R3 R5 P3 N3 K1")),
-        Subsignal("dm", Pins("R6","T5")),
+        Subsignal("dm", Pins("R6 T5")),
         IOStandard("3.3-V LVTTL")
     ),
 
diff --git a/mibuild/sim/verilator.py b/mibuild/sim/verilator.py
index e0d7ff33b..cc7313c85 100644
--- a/mibuild/sim/verilator.py
+++ b/mibuild/sim/verilator.py
@@ -100,7 +100,7 @@ make -j -C obj_dir/ -f Vdut.mk Vdut
     build_script_file = "build_" + build_name + ".sh"
     tools.write_to_file(build_script_file, build_script_contents, force_unix=True)
 
-    _build_tb(platform, vns, serial, os.path.join("..", sim_path,"dut_tb.cpp"))
+    _build_tb(platform, vns, serial, os.path.join("..", sim_path, "dut_tb.cpp"))
     if verbose:
         r = subprocess.call(["bash", build_script_file])
     else:
diff --git a/migen/fhdl/edif.py b/migen/fhdl/edif.py
index 8222bd68a..32c3cf9f5 100644
--- a/migen/fhdl/edif.py
+++ b/migen/fhdl/edif.py
@@ -137,7 +137,7 @@ def _generate_cells(f):
     return [_Cell(k, v) for k, v in cell_dict.items()]
 
 
-def _generate_instances(f,ns):
+def _generate_instances(f, ns):
     instances = []
     for special in f.specials:
         if isinstance(special, Instance):
diff --git a/migen/genlib/roundrobin.py b/migen/genlib/roundrobin.py
index 2d28b8a4a..5dd56759d 100644
--- a/migen/genlib/roundrobin.py
+++ b/migen/genlib/roundrobin.py
@@ -17,7 +17,7 @@ class RoundRobin(Module):
             cases = {}
             for i in range(n):
                 switch = []
-                for j in reversed(range(i+1,i+n)):
+                for j in reversed(range(i+1, i+n)):
                     t = j % n
                     switch = [
                         If(self.request[t],