Reverted the addition of a NORMALIZE_NUMBERS option, per Tim Peter's

request.  Tim says that "correct 'fuzzy' comparison of floats cannot
be automated."  (The motivation behind adding the new option
was verifying interactive examples in Python's latex documentation;
several such examples use numbers that don't print consistently on
different platforms.)

1 files changed, 1 insertions, 79 deletions

diff --git a/Lib/doctest.py b/Lib/doctest.py
index dfd8bb9..26a8914 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -55,7 +55,6 @@ __all__ = [
     'NORMALIZE_WHITESPACE',
     'ELLIPSIS',
     'IGNORE_EXCEPTION_DETAIL',
-    'NORMALIZE_NUMBERS',
     'COMPARISON_FLAGS',
     'REPORT_UDIFF',
     'REPORT_CDIFF',
@@ -140,14 +139,12 @@ DONT_ACCEPT_BLANKLINE = register_optionflag('DONT_ACCEPT_BLANKLINE')
 NORMALIZE_WHITESPACE = register_optionflag('NORMALIZE_WHITESPACE')
 ELLIPSIS = register_optionflag('ELLIPSIS')
 IGNORE_EXCEPTION_DETAIL = register_optionflag('IGNORE_EXCEPTION_DETAIL')
-NORMALIZE_NUMBERS = register_optionflag('NORMALIZE_NUMBERS')
 
 COMPARISON_FLAGS = (DONT_ACCEPT_TRUE_FOR_1 |
                     DONT_ACCEPT_BLANKLINE |
                     NORMALIZE_WHITESPACE |
                     ELLIPSIS |
-                    IGNORE_EXCEPTION_DETAIL |
-                    NORMALIZE_NUMBERS)
+                    IGNORE_EXCEPTION_DETAIL)
 
 REPORT_UDIFF = register_optionflag('REPORT_UDIFF')
 REPORT_CDIFF = register_optionflag('REPORT_CDIFF')
@@ -280,72 +277,6 @@ class _SpoofOut(StringIO):
         if hasattr(self, "softspace"):
             del self.softspace
 
-# The number of digits of precision that must be equal for
-# NORMALIZE_NUMBERS to consider two numbers equal.
-_NORMALIZE_NUMBERS_PRECISION_THRESHOLD = 10
-
-# A regular expression that matches Python number literals.  This is
-# used by _normalize_numbers to look for numbers that should be
-# normalized.
-_NUMBER_LITERAL = re.compile(r'''
-    (\d+[.]\d*(?:[eE][-+]?\d+)?[jJ]? | # float (w/ digits left of ".")
-        [.]\d+(?:[eE][-+]?\d+)?[jJ]? | # float (no digits left of ".")
-     \d+      (?:[eE][-+]?\d+) [jJ]? | # float (no ".", exponent only)
-     \d                        [jJ]  | # float (no ".", imaginary only)
-     0[xX]\d+[lL]?                   | # hexint
-     0[0-7]*[lL]?                    | # octint or zero
-     \d+[lL]?                        ) # decint
-     ''', re.VERBOSE)
-
-def _normalize_numbers(want, got):
-    """
-    If all the numbers in `want` and `got` match (one-for-one), then
-    return a new version of `got` with the exact number strings from
-    `want` spliced in.  Two numbers match if `str` of their float
-    values are equal.  (I.e., `x` matches `y` if
-    `str(float(x))==str(float(y))`).
-    """
-    want_pieces = _NUMBER_LITERAL.split(want)
-    got_pieces = _NUMBER_LITERAL.split(got)
-
-    # If they don't have the same number of numbers, fail immediately.
-    if len(want_pieces) != len(got_pieces):
-        return got
-
-    # If any individual numbers don't match, then fail.
-    for i in range(1, len(got_pieces), 2):
-        w, g = eval(want_pieces[i]), eval(got_pieces[i])
-        if not _numbers_match(w, g):
-            return got
-
-    # Success; replace numbers in got w/ numbers from want.
-    for i in range(1, len(got_pieces), 2):
-        got_pieces[i] = want_pieces[i]
-    return ''.join(got_pieces)
-
-def _numbers_match(x, y):
-    """
-    A helper function for _normalize_numbers, that returns true if the
-    numbers `x` and `y` are close enough to match for NORMALIZE_NUMBERS.
-    """
-    # Equal numbers match.
-    if x == y:
-        return True
-    # Split up complex numbers into real & imag.
-    if isinstance(x, complex):
-        return (isinstance(y, complex) and
-                _numbers_match(x.real, y.real) and
-                _numbers_match(x.imag, y.imag))
-    # If the signs are different, they don't match.
-    if x*y < 0:
-        return False
-    # If one is zero and the other isn't, they don't match.
-    if x==0 or y==0:
-        return False
-    # They're not exactly equal, but are they close enough?
-    threshold = 10**-_NORMALIZE_NUMBERS_PRECISION_THRESHOLD
-    return (abs(x-y) / min(abs(x), abs(y))) < threshold
-
 # Worst-case linear-time ellipsis matching.
 def _ellipsis_match(want, got):
     """
@@ -1572,13 +1503,6 @@ class OutputChecker:
             if got == want:
                 return True
 
-        # This flag causes doctest to treat numbers that are within a
-        # small threshold as if they are equal.
-        if optionflags & NORMALIZE_NUMBERS:
-            got = _normalize_numbers(want, got)
-            if got == want:
-                return True
-
         # The ELLIPSIS flag says to let the sequence "..." in `want`
         # match any substring in `got`.
         if optionflags & ELLIPSIS:
@@ -1859,7 +1783,6 @@ def testmod(m=None, name=None, globs=None, verbose=None, isprivate=None,
         NORMALIZE_WHITESPACE
         ELLIPSIS
         IGNORE_EXCEPTION_DETAIL
-        NORMALIZE_NUMBERS
         REPORT_UDIFF
         REPORT_CDIFF
         REPORT_NDIFF
@@ -1982,7 +1905,6 @@ def testfile(filename, module_relative=True, name=None, package=None,
         NORMALIZE_WHITESPACE
         ELLIPSIS
         IGNORE_EXCEPTION_DETAIL
-        NORMALIZE_NUMBERS
         REPORT_UDIFF
         REPORT_CDIFF
         REPORT_NDIFF