Address review comments.

Author: serhiy-storchaka

Lib/test/test_fractions.py

@@ -7,6 +7,7 @@
 import operator
 import fractions
 import functools
+import os
 import sys
 import typing
 import unittest
@@ -15,6 +16,9 @@
 from pickle import dumps, loads
 F = fractions.Fraction
 
+#locate file with float format test values
+test_dir = os.path.dirname(__file__) or os.curdir
+format_testfile = os.path.join(test_dir, 'formatfloat_testcases.txt')
 
 class DummyFloat(object):
     """Dummy float class for testing comparisons with Fractions"""
@@ -1222,7 +1226,6 @@ def test_invalid_formats(self):
 
     @requires_IEEE_754
     def test_float_format_testfile(self):
-        from test.test_float import format_testfile
         with open(format_testfile, encoding="utf-8") as testfile:
             for line in testfile:
                 if line.startswith('--'):
@@ -1235,14 +1238,15 @@ def test_float_format_testfile(self):
                 fmt, arg = lhs.split()
                 if fmt == '%r':
                     continue
+                fmt2 = fmt[1:]
                 with self.subTest(fmt=fmt, arg=arg):
                     f = F(float(arg))
-                    self.assertEqual(format(f, fmt[1:]), rhs)
+                    self.assertEqual(format(f, fmt2), rhs)
                     if f:  # skip negative zero
-                        self.assertEqual(format(-f, fmt[1:]), '-' + rhs)
+                        self.assertEqual(format(-f, fmt2), '-' + rhs)
                     f = F(arg)
-                    self.assertEqual(float(format(f, fmt[1:])), float(rhs))
-                    self.assertEqual(float(format(-f, fmt[1:])), float('-' + rhs))
+                    self.assertEqual(float(format(f, fmt2)), float(rhs))
+                    self.assertEqual(float(format(-f, fmt2)), float('-' + rhs))
 
 
 if __name__ == '__main__':