Modernize code to Python 3.6+ and some cleanup

02-array-seq/listcomp_speed.py

@@ -10,7 +10,7 @@ def non_ascii(c):
 
 def clock(label, cmd):
     res = timeit.repeat(cmd, setup=SETUP, number=TIMES)
-    print(label, *('{:.3f}'.format(x) for x in res))
+    print(label, *(f'{x:.3f}' for x in res))
 
 clock('listcomp        :', '[ord(s) for s in symbols if ord(s) > 127]')
 clock('listcomp + func :', '[ord(s) for s in symbols if non_ascii(ord(s))]')