diff --git a/tests/README b/tests/README
index ef00705712..0cb526c3b4 100644
--- a/tests/README
+++ b/tests/README
@@ -2,3 +2,7 @@ This directory contains tests for various functionality areas of MicroPython.
 To run all stable tests, run "run-tests" script in this directory. Note
 that bytecode tests are not yet stable and should be run separately in
 "bytecode" subdirectory.
+
+When creating new tests, anything that relies on float support should go in the 
+float/ subdirectory.  Anything that relies on import x, where x is not a built-in
+module, should go in the import/ subdirectory.
diff --git a/tests/basics/int-divzero.py b/tests/basics/int-divzero.py
index d1fc579321..28ec2a6995 100644
--- a/tests/basics/int-divzero.py
+++ b/tests/basics/int-divzero.py
@@ -1,8 +1,3 @@
-try:
-    1 / 0
-except ZeroDivisionError:
-    print("ZeroDivisionError")
-
 try:
     1 // 0
 except ZeroDivisionError:
diff --git a/tests/basics/list1.py b/tests/basics/list1.py
index a0c8afc4f8..c8317baa3d 100644
--- a/tests/basics/list1.py
+++ b/tests/basics/list1.py
@@ -22,8 +22,3 @@ print(x)
 print(x[1:])
 print(x[:-1])
 print(x[2:3])
-
-try:
-    print(x[1.0])
-except TypeError:
-    print("TypeError")
diff --git a/tests/basics/modulo.py b/tests/basics/modulo.py
index 4d83db6ec8..c95305d13d 100644
--- a/tests/basics/modulo.py
+++ b/tests/basics/modulo.py
@@ -1,5 +1,6 @@
 # check modulo matches python definition
-# This test compiler version
+
+# this tests compiler constant folding
 print(123 % 7)
 print(-123 % 7)
 print(123 % -7)
@@ -20,17 +21,3 @@ print(a % b)
 print(a % -b)
 print(-a % b)
 print(-a % -b)
-
-if False:
-	print(1.23456 % 0.7)
-	print(-1.23456 % 0.7)
-	print(1.23456 % -0.7)
-	print(-1.23456 % -0.7)
-
-	a = 1.23456
-	b = 0.7
-	print(a % b)
-	print(a % -b)
-	print(-a % b)
-	print(-a % -b)
-
diff --git a/tests/basics/string-format-modulo.py b/tests/basics/string-format-modulo.py
index 8e58be18c8..0e2c1d1096 100644
--- a/tests/basics/string-format-modulo.py
+++ b/tests/basics/string-format-modulo.py
@@ -23,11 +23,9 @@ except TypeError:
 
 print("%s" % True)
 print("%s" % 1)
-print("%s" % 1.0)
 
 print("%r" % True)
 print("%r" % 1)
-print("%r" % 1.0)
 
 print("%c" % 48)
 print("%c" % 'a')
@@ -37,28 +35,16 @@ print("%d" % 10)
 print("%+d" % 10)
 print("% d" % 10)
 print("%d" % -10)
-print("%d" % 1.0)
 print("%d" % True)
 print("%i" % -10)
-print("%i" % 1.0)
 print("%i" % True)
 print("%u" % -10)
-print("%u" % 1.0)
 print("%u" % True)
 print("%x" % 18)
-print("%x" % 18.0)
 print("%o" % 18)
-print("%o" % 18.0)
 print("%X" % 18)
-print("%X" % 18.0)
 print("%#x" % 18)
 print("%#X" % 18)
 print("%#6o" % 18)
 print("%#6x" % 18)
 print("%#06x" % 18)
-print("%e" % 1.23456)
-print("%E" % 1.23456)
-print("%f" % 1.23456)
-print("%F" % 1.23456)
-print("%g" % 1.23456)
-print("%G" % 1.23456)
diff --git a/tests/basics/string-format.py b/tests/basics/string-format.py
index 2d6d0cc721..84ea054758 100644
--- a/tests/basics/string-format.py
+++ b/tests/basics/string-format.py
@@ -60,26 +60,6 @@ test("{:@<6d}",  -123)
 test("{:@=6d}",  -123)
 test("{:06d}",  -123)
 
-test("{:10.4e}", 123.456)
-test("{:10.4e}", -123.456)
-test("{:10.4f}", 123.456)
-test("{:10.4f}", -123.456)
-test("{:10.4g}", 123.456)
-test("{:10.4g}", -123.456)
-test("{:e}", 100)
-test("{:f}", 200)
-test("{:g}", 300)
-
-test("{:10.4E}", 123.456)
-test("{:10.4E}", -123.456)
-test("{:10.4F}", 123.456)
-test("{:10.4F}", -123.456)
-test("{:10.4G}", 123.456)
-test("{:10.4G}", -123.456)
-
-# The following fails right now
-#test("{:10.1}", 0.0)
-
 def test_fmt(conv, fill, alignment, sign, prefix, width, precision, type, arg):
     fmt = '{'
     if conv:
@@ -137,71 +117,4 @@ if full_tests:
                     for str in ('', 'a', 'bcd', 'This is a test with a longer string'):
                         test_fmt(conv, fill, alignment, '', '', width, '', 's', str)
 
-eg_nums = (0.0, -0.0, 0.1, 1.234, 12.3459, 1.23456789, 123456789.0, -0.0,
-    -0.1, -1.234, -12.3459, 1e4, 1e-4, 1e5, 1e-5, 1e6, 1e-6, 1e10,
-    1e37, -1e37, 1e-37, -1e-37,
-    1.23456e8, 1.23456e7, 1.23456e6, 1.23456e5, 1.23456e4, 1.23456e3, 1.23456e2, 1.23456e1, 1.23456e0,
-    1.23456e-1, 1.23456e-2, 1.23456e-3, 1.23456e-4, 1.23456e-5, 1.23456e-6, 1.23456e-7, 1.23456e-8,
-    -1.23456e8, -1.23456e7, -1.23456e6, -1.23456e5, -1.23456e4, -1.23456e3, -1.23456e2, -1.23456e1, -1.23456e0,
-    -1.23456e-1, -1.23456e-2, -1.23456e-3, -1.23456e-4, -1.23456e-5, -1.23456e-6, -1.23456e-7, -1.23456e-8)
-
-if full_tests:
-    for type in ('e', 'E', 'g', 'G', 'n'):
-        for width in ('', '4', '6', '8', '10'):
-            for alignment in ('', '<', '>', '=', '^'):
-                for fill in ('', '@', '0', ' '):
-                    for sign in ('', '+', '-', ' '):
-                        for prec in ('', '1', '3', '6'):
-                            for num in eg_nums:
-                                test_fmt('', fill, alignment, sign, '', width, prec, type, num)
-
-# Note: We use 1.23459 rather than 1.2345 because '{:3f}'.format(1.2345)
-#       rounds differently than print("%.3f", 1.2345);
-
-f_nums = (0.0, -0.0, 0.0001, 0.001, 0.01, 0.1, 1.0, 10.0,
-     0.0012,  0.0123,  0.1234,  1.23459,  12.3456,
-    -0.0001, -0.001,  -0.01,   -0.1,      -1.0, -10.0,
-    -0.0012, -0.0123, -0.1234, -1.23459, -12.3456)
-
-if full_tests:
-    for type in ('f', 'F'):
-        for width in ('', '4', '6', '8', '10'):
-            for alignment in ('', '<', '>', '=', '^'):
-                for fill in ('', ' ', '0', '@'):
-                    for sign in ('', '+', '-', ' '):
-                        # An empty precision defaults to 6, but when uPy is
-                        # configured to use a float, we can only use a
-                        # precision of 6 with numbers less than 10 and still
-                        # get results that compare to CPython (which uses
-                        # long doubles).
-                        for prec in ('1', '2', '3'):
-                            for num in f_nums:
-                                test_fmt('', fill, alignment, sign, '', width, prec, type, num)
-                        for num in int_nums2:
-                            test_fmt('', fill, alignment, sign, '', width, '', type, num)
-
-pct_nums1 = (0.1, 0.58, 0.99, -0.1, -0.58, -0.99)
-pct_nums2 = (True, False, 1, 0, -1)
-
-if full_tests:
-    type = '%'
-    for width in ('', '4', '6', '8', '10'):
-        for alignment in ('', '<', '>', '=', '^'):
-            for fill in ('', ' ', '0', '@'):
-                for sign in ('', '+', '-', ' '):
-                    # An empty precision defaults to 6, but when uPy is
-                    # configured to use a float, we can only use a
-                    # precision of 6 with numbers less than 10 and still
-                    # get results that compare to CPython (which uses
-                    # long doubles).
-                    for prec in ('1', '2', '3'):
-                        for num in pct_nums1:
-                            test_fmt('', fill, alignment, sign, '', width, prec, type, num)
-                    for num in pct_nums2:
-                        test_fmt('', fill, alignment, sign, '', width, '', type, num)
-
-# We don't currently test a type of '' with floats (see the detailed comment
-# in  objstr.c)
-
 # TODO Add tests for erroneous format strings.
-
diff --git a/tests/basics/true-value.py b/tests/basics/true-value.py
index 1dd547f326..9ec209fe82 100644
--- a/tests/basics/true-value.py
+++ b/tests/basics/true-value.py
@@ -9,12 +9,6 @@ if not None:
 if not 0:
     print("0")
 
-if not 0.0:
-    print("float 0")
-
-if not 0+0j:
-    print("complex 0")
-
 if not "":
     print("Empty string")
 if "foo":
diff --git a/tests/basics/types1.py b/tests/basics/types1.py
index 57b33b842b..38a20d6803 100644
--- a/tests/basics/types1.py
+++ b/tests/basics/types1.py
@@ -2,8 +2,6 @@
 
 print(bool)
 print(int)
-print(float)
-print(complex)
 print(tuple)
 print(list)
 print(set)
@@ -11,8 +9,6 @@ print(dict)
 
 print(type(bool()) == bool)
 print(type(int()) == int)
-print(type(float()) == float)
-print(type(complex()) == complex)
 print(type(tuple()) == tuple)
 print(type(list()) == list)
 print(type(set()) == set)
@@ -20,8 +16,6 @@ print(type(dict()) == dict)
 
 print(type(False) == bool)
 print(type(0) == int)
-print(type(0.0) == float)
-print(type(1j) == complex)
 print(type(()) == tuple)
 print(type([]) == list)
 print(type({None}) == set)
diff --git a/tests/basics/types2.py b/tests/basics/types2.py
index 83a69c918f..ba7be6b154 100644
--- a/tests/basics/types2.py
+++ b/tests/basics/types2.py
@@ -9,4 +9,6 @@ print(int == int)
 print(int != list)
 
 d = {}
-d[int] = float
+d[int] = list
+d[list] = int
+print(len(d))
diff --git a/tests/basics/float1.py b/tests/float/float1.py
similarity index 100%
rename from tests/basics/float1.py
rename to tests/float/float1.py
diff --git a/tests/float/int-divzero.py b/tests/float/int-divzero.py
new file mode 100644
index 0000000000..b037dd8c7b
--- /dev/null
+++ b/tests/float/int-divzero.py
@@ -0,0 +1,4 @@
+try:
+    1 / 0
+except ZeroDivisionError:
+    print("ZeroDivisionError")
diff --git a/tests/float/list-index.py b/tests/float/list-index.py
new file mode 100644
index 0000000000..13e4557af7
--- /dev/null
+++ b/tests/float/list-index.py
@@ -0,0 +1,8 @@
+x = [1, 2]
+
+print(x[1])
+
+try:
+    print(x[1.0])
+except TypeError:
+    print("TypeError")
diff --git a/tests/basics/math-fun-bool.py b/tests/float/math-fun-bool.py
similarity index 100%
rename from tests/basics/math-fun-bool.py
rename to tests/float/math-fun-bool.py
diff --git a/tests/basics/math-fun.py b/tests/float/math-fun.py
similarity index 100%
rename from tests/basics/math-fun.py
rename to tests/float/math-fun.py
diff --git a/tests/float/modulo.py b/tests/float/modulo.py
new file mode 100644
index 0000000000..911268513a
--- /dev/null
+++ b/tests/float/modulo.py
@@ -0,0 +1,14 @@
+# check modulo matches python definition
+# TODO we currenty fail with this
+if False:
+	print(1.23456 % 0.7)
+	print(-1.23456 % 0.7)
+	print(1.23456 % -0.7)
+	print(-1.23456 % -0.7)
+
+	a = 1.23456
+	b = 0.7
+	print(a % b)
+	print(a % -b)
+	print(-a % b)
+	print(-a % -b)
diff --git a/tests/float/string-format-modulo.py b/tests/float/string-format-modulo.py
new file mode 100644
index 0000000000..f2117f3565
--- /dev/null
+++ b/tests/float/string-format-modulo.py
@@ -0,0 +1,16 @@
+print("%s" % 1.0)
+print("%r" % 1.0)
+
+print("%d" % 1.0)
+print("%i" % 1.0)
+print("%u" % 1.0)
+print("%x" % 18.0)
+print("%o" % 18.0)
+print("%X" % 18.0)
+
+print("%e" % 1.23456)
+print("%E" % 1.23456)
+print("%f" % 1.23456)
+print("%F" % 1.23456)
+print("%g" % 1.23456)
+print("%G" % 1.23456)
diff --git a/tests/float/string-format.py b/tests/float/string-format.py
new file mode 100644
index 0000000000..b5ff68b8ca
--- /dev/null
+++ b/tests/float/string-format.py
@@ -0,0 +1,123 @@
+# Change the following to True to get a much more comprehensive set of tests
+# to run, albeit, which take considerably longer.
+
+full_tests = False
+
+def test(fmt, *args):
+    print('{:8s}'.format(fmt) + '>' +  fmt.format(*args) + '<')
+
+test("{:10.4e}", 123.456)
+test("{:10.4e}", -123.456)
+test("{:10.4f}", 123.456)
+test("{:10.4f}", -123.456)
+test("{:10.4g}", 123.456)
+test("{:10.4g}", -123.456)
+test("{:e}", 100)
+test("{:f}", 200)
+test("{:g}", 300)
+
+test("{:10.4E}", 123.456)
+test("{:10.4E}", -123.456)
+test("{:10.4F}", 123.456)
+test("{:10.4F}", -123.456)
+test("{:10.4G}", 123.456)
+test("{:10.4G}", -123.456)
+
+# The following fails right now
+#test("{:10.1}", 0.0)
+
+def test_fmt(conv, fill, alignment, sign, prefix, width, precision, type, arg):
+    fmt = '{'
+    if conv:
+        fmt += '!'
+        fmt += conv
+    fmt += ':'
+    if alignment:
+        fmt += fill
+        fmt += alignment
+    fmt += sign
+    fmt += prefix
+    fmt += width
+    if precision:
+        fmt += '.'
+        fmt += precision
+    fmt += type
+    fmt += '}'
+    test(fmt,  arg)
+    if fill == '0' and alignment == '=':
+        fmt = '{:'
+        fmt += sign
+        fmt += prefix
+        fmt += width
+        if precision:
+            fmt += '.'
+            fmt += precision
+        fmt += type
+        fmt += '}'
+        test(fmt, arg)
+
+eg_nums = (0.0, -0.0, 0.1, 1.234, 12.3459, 1.23456789, 123456789.0, -0.0,
+    -0.1, -1.234, -12.3459, 1e4, 1e-4, 1e5, 1e-5, 1e6, 1e-6, 1e10,
+    1e37, -1e37, 1e-37, -1e-37,
+    1.23456e8, 1.23456e7, 1.23456e6, 1.23456e5, 1.23456e4, 1.23456e3, 1.23456e2, 1.23456e1, 1.23456e0,
+    1.23456e-1, 1.23456e-2, 1.23456e-3, 1.23456e-4, 1.23456e-5, 1.23456e-6, 1.23456e-7, 1.23456e-8,
+    -1.23456e8, -1.23456e7, -1.23456e6, -1.23456e5, -1.23456e4, -1.23456e3, -1.23456e2, -1.23456e1, -1.23456e0,
+    -1.23456e-1, -1.23456e-2, -1.23456e-3, -1.23456e-4, -1.23456e-5, -1.23456e-6, -1.23456e-7, -1.23456e-8)
+
+if full_tests:
+    for type in ('e', 'E', 'g', 'G', 'n'):
+        for width in ('', '4', '6', '8', '10'):
+            for alignment in ('', '<', '>', '=', '^'):
+                for fill in ('', '@', '0', ' '):
+                    for sign in ('', '+', '-', ' '):
+                        for prec in ('', '1', '3', '6'):
+                            for num in eg_nums:
+                                test_fmt('', fill, alignment, sign, '', width, prec, type, num)
+
+# Note: We use 1.23459 rather than 1.2345 because '{:3f}'.format(1.2345)
+#       rounds differently than print("%.3f", 1.2345);
+
+f_nums = (0.0, -0.0, 0.0001, 0.001, 0.01, 0.1, 1.0, 10.0,
+     0.0012,  0.0123,  0.1234,  1.23459,  12.3456,
+    -0.0001, -0.001,  -0.01,   -0.1,      -1.0, -10.0,
+    -0.0012, -0.0123, -0.1234, -1.23459, -12.3456)
+
+if full_tests:
+    for type in ('f', 'F'):
+        for width in ('', '4', '6', '8', '10'):
+            for alignment in ('', '<', '>', '=', '^'):
+                for fill in ('', ' ', '0', '@'):
+                    for sign in ('', '+', '-', ' '):
+                        # An empty precision defaults to 6, but when uPy is
+                        # configured to use a float, we can only use a
+                        # precision of 6 with numbers less than 10 and still
+                        # get results that compare to CPython (which uses
+                        # long doubles).
+                        for prec in ('1', '2', '3'):
+                            for num in f_nums:
+                                test_fmt('', fill, alignment, sign, '', width, prec, type, num)
+                        for num in int_nums2:
+                            test_fmt('', fill, alignment, sign, '', width, '', type, num)
+
+pct_nums1 = (0.1, 0.58, 0.99, -0.1, -0.58, -0.99)
+pct_nums2 = (True, False, 1, 0, -1)
+
+if full_tests:
+    type = '%'
+    for width in ('', '4', '6', '8', '10'):
+        for alignment in ('', '<', '>', '=', '^'):
+            for fill in ('', ' ', '0', '@'):
+                for sign in ('', '+', '-', ' '):
+                    # An empty precision defaults to 6, but when uPy is
+                    # configured to use a float, we can only use a
+                    # precision of 6 with numbers less than 10 and still
+                    # get results that compare to CPython (which uses
+                    # long doubles).
+                    for prec in ('1', '2', '3'):
+                        for num in pct_nums1:
+                            test_fmt('', fill, alignment, sign, '', width, prec, type, num)
+                    for num in pct_nums2:
+                        test_fmt('', fill, alignment, sign, '', width, '', type, num)
+
+# We don't currently test a type of '' with floats (see the detailed comment
+# in  objstr.c)
diff --git a/tests/float/true-value.py b/tests/float/true-value.py
new file mode 100644
index 0000000000..df415f0031
--- /dev/null
+++ b/tests/float/true-value.py
@@ -0,0 +1,7 @@
+# Test true-ish value handling
+
+if not 0.0:
+    print("float 0")
+
+if not 0+0j:
+    print("complex 0")
diff --git a/tests/float/types.py b/tests/float/types.py
new file mode 100644
index 0000000000..75674c9246
--- /dev/null
+++ b/tests/float/types.py
@@ -0,0 +1,17 @@
+# float types
+
+print(float)
+print(complex)
+
+print(type(float()) == float)
+print(type(complex()) == complex)
+
+print(type(0.0) == float)
+print(type(1j) == complex)
+
+# hashing float types
+
+d = dict()
+d[float] = complex
+d[complex] = float
+print(len(d))
diff --git a/tests/basics/import-pkg1.py b/tests/import/import-pkg1.py
similarity index 100%
rename from tests/basics/import-pkg1.py
rename to tests/import/import-pkg1.py
diff --git a/tests/basics/import-pkg2.py b/tests/import/import-pkg2.py
similarity index 100%
rename from tests/basics/import-pkg2.py
rename to tests/import/import-pkg2.py
diff --git a/tests/basics/import-pkg3.py b/tests/import/import-pkg3.py
similarity index 100%
rename from tests/basics/import-pkg3.py
rename to tests/import/import-pkg3.py
diff --git a/tests/basics/import-pkg4.py b/tests/import/import-pkg4.py
similarity index 100%
rename from tests/basics/import-pkg4.py
rename to tests/import/import-pkg4.py
diff --git a/tests/basics/import-pkg5.py b/tests/import/import-pkg5.py
similarity index 100%
rename from tests/basics/import-pkg5.py
rename to tests/import/import-pkg5.py
diff --git a/tests/basics/import1a.py b/tests/import/import1a.py
similarity index 100%
rename from tests/basics/import1a.py
rename to tests/import/import1a.py
diff --git a/tests/basics/import1b.py b/tests/import/import1b.py
similarity index 100%
rename from tests/basics/import1b.py
rename to tests/import/import1b.py
diff --git a/tests/basics/import2a.py b/tests/import/import2a.py
similarity index 100%
rename from tests/basics/import2a.py
rename to tests/import/import2a.py
diff --git a/tests/basics/import3a.py b/tests/import/import3a.py
similarity index 100%
rename from tests/basics/import3a.py
rename to tests/import/import3a.py
diff --git a/tests/basics/pkg/__init__.py b/tests/import/pkg/__init__.py
similarity index 100%
rename from tests/basics/pkg/__init__.py
rename to tests/import/pkg/__init__.py
diff --git a/tests/basics/pkg/mod.py b/tests/import/pkg/mod.py
similarity index 100%
rename from tests/basics/pkg/mod.py
rename to tests/import/pkg/mod.py
diff --git a/tests/basics/pkg2/__init__.py b/tests/import/pkg2/__init__.py
similarity index 100%
rename from tests/basics/pkg2/__init__.py
rename to tests/import/pkg2/__init__.py
diff --git a/tests/basics/pkg2/mod1.py b/tests/import/pkg2/mod1.py
similarity index 100%
rename from tests/basics/pkg2/mod1.py
rename to tests/import/pkg2/mod1.py
diff --git a/tests/basics/pkg2/mod2.py b/tests/import/pkg2/mod2.py
similarity index 100%
rename from tests/basics/pkg2/mod2.py
rename to tests/import/pkg2/mod2.py
diff --git a/tests/basics/pkg3/__init__.py b/tests/import/pkg3/__init__.py
similarity index 100%
rename from tests/basics/pkg3/__init__.py
rename to tests/import/pkg3/__init__.py
diff --git a/tests/basics/pkg3/mod1.py b/tests/import/pkg3/mod1.py
similarity index 100%
rename from tests/basics/pkg3/mod1.py
rename to tests/import/pkg3/mod1.py
diff --git a/tests/basics/pkg3/mod2.py b/tests/import/pkg3/mod2.py
similarity index 100%
rename from tests/basics/pkg3/mod2.py
rename to tests/import/pkg3/mod2.py
diff --git a/tests/basics/pkg3/subpkg1/__init__.py b/tests/import/pkg3/subpkg1/__init__.py
similarity index 100%
rename from tests/basics/pkg3/subpkg1/__init__.py
rename to tests/import/pkg3/subpkg1/__init__.py
diff --git a/tests/basics/pkg3/subpkg1/mod1.py b/tests/import/pkg3/subpkg1/mod1.py
similarity index 100%
rename from tests/basics/pkg3/subpkg1/mod1.py
rename to tests/import/pkg3/subpkg1/mod1.py
diff --git a/tests/basics/try-module.py b/tests/import/try-module.py
similarity index 100%
rename from tests/basics/try-module.py
rename to tests/import/try-module.py
diff --git a/tests/run-tests b/tests/run-tests
index bd6e50bbd2..da18c6c765 100755
--- a/tests/run-tests
+++ b/tests/run-tests
@@ -29,7 +29,8 @@ failed_tests = []
 tests = []
 
 if not sys.argv[1:]:
-    tests = sorted(glob('basics/*.py') + glob('io/*.py') + glob('misc/*.py'))
+    test_dirs = ('basics', 'float', 'import', 'io', 'misc')
+    tests = sorted(test_file for test_files in (glob('{}/*.py'.format(dir)) for dir in test_dirs) for test_file in test_files)
 else:
     tests = sys.argv[1:]
 
@@ -56,13 +57,9 @@ for test_file in tests:
     if test_on_pyboard:
         pyb.enter_raw_repl()
         try:
-            if test_file == 'basics/memoryerror.py':
-                # this test crashes the pyboard
-                output_mupy = b'CRASH'
-            else:
-                output_mupy = pyb.execfile(test_file).replace(b'\r\n', b'\n')
+            output_mupy = pyb.execfile(test_file).replace(b'\r\n', b'\n')
         except pyboard.PyboardError:
-            output_mupy = b'CRASH\n' + output_mupy
+            output_mupy = b'CRASH'
     else:
         try:
             output_mupy = subprocess.check_output([MP_PY, '-X', 'emit=bytecode', test_file])