1 '''

     2    Tests for fpformat module

     3    Nick Mathewson

     4 '''

     5 from test.test_support import run_unittest, import_module

     6 import unittest

     7 fpformat = import_module('fpformat', deprecated=True)

     8 fix, sci, NotANumber = fpformat.fix, fpformat.sci, fpformat.NotANumber

     9 

    10 StringType = type('')

    11 

    12 # Test the old and obsolescent fpformat module.

    13 #

    14 # (It's obsolescent because fix(n,d) == "%.*f"%(d,n) and

    15 #                           sci(n,d) == "%.*e"%(d,n)

    16 #  for all reasonable numeric n and d, except that sci gives 3 exponent

    17 #  digits instead of 2.

    18 #

    19 # Differences only occur for unreasonable n and d.    <.2 wink>)

    20 

    21 class FpformatTest(unittest.TestCase):

    22 

    23     def checkFix(self, n, digits):

    24         result = fix(n, digits)

    25         if isinstance(n, StringType):

    26             n = repr(n)

    27         expected = "%.*f" % (digits, float(n))

    28 

    29         self.assertEquals(result, expected)

    30 

    31     def checkSci(self, n, digits):

    32         result = sci(n, digits)

    33         if isinstance(n, StringType):

    34             n = repr(n)

    35         expected = "%.*e" % (digits, float(n))

    36         # add the extra 0 if needed

    37         num, exp = expected.split("e")

    38         if len(exp) < 4:

    39             exp = exp[0] + "0" + exp[1:]

    40         expected = "%se%s" % (num, exp)

    41 

    42         self.assertEquals(result, expected)

    43 

    44     def test_basic_cases(self):

    45         self.assertEquals(fix(100.0/3, 3), '33.333')

    46         self.assertEquals(sci(100.0/3, 3), '3.333e+001')

    47 

    48     def test_reasonable_values(self):

    49         for d in range(7):

    50             for val in (1000.0/3, 1000, 1000.0, .002, 1.0/3, 1e10):

    51                 for realVal in (val, 1.0/val, -val, -1.0/val):

    52                     self.checkFix(realVal, d)

    53                     self.checkSci(realVal, d)

    54 

    55     def test_failing_values(self):

    56         # Now for 'unreasonable n and d'

    57         self.assertEquals(fix(1.0, 1000), '1.'+('0'*1000))

    58         self.assertEquals(sci("1"+('0'*1000), 0), '1e+1000')

    59 

    60         # This behavior is inconsistent.  sci raises an exception; fix doesn't.

    61         yacht = "Throatwobbler Mangrove"

    62         self.assertEquals(fix(yacht, 10), yacht)

    63         try:

    64             sci(yacht, 10)

    65         except NotANumber:

    66             pass

    67         else:

    68             self.fail("No exception on non-numeric sci")

    69 

    70 

    71 def test_main():

    72     run_unittest(FpformatTest)

    73 

    74 

    75 if __name__ == "__main__":

    76     test_main()