Lib/test/test_tokenize.py

from test import test_support
from tokenize import (untokenize, generate_tokens, NUMBER, NAME, OP,
                     STRING, ENDMARKER, tok_name, Untokenizer, tokenize)
from StringIO import StringIO
import os
from unittest import TestCase


class TokenizeTest(TestCase):
    # Tests for the tokenize module.

    # The tests can be really simple. Given a small fragment of source
    # code, print out a table with tokens. The ENDMARKER is omitted for
    # brevity.

    def check_tokenize(self, s, expected):
        # Format the tokens in s in a table format.
        # The ENDMARKER is omitted.
        result = []
        f = StringIO(s)
        for type, token, start, end, line in generate_tokens(f.readline):
            if type == ENDMARKER:
                break
            type = tok_name[type]
            result.append("    %(type)-10.10s %(token)-13.13r %(start)s %(end)s" %
                          locals())
        self.assertEqual(result,
                         expected.rstrip().splitlines())


    def test_basic(self):
        self.check_tokenize("1 + 1", """\
    NUMBER     '1'           (1, 0) (1, 1)
    OP         '+'           (1, 2) (1, 3)
    NUMBER     '1'           (1, 4) (1, 5)
    """)
        self.check_tokenize("if False:\n"
                            "    # NL\n"
                            "    True = False # NEWLINE\n", """\
    NAME       'if'          (1, 0) (1, 2)
    NAME       'False'       (1, 3) (1, 8)
    OP         ':'           (1, 8) (1, 9)
    NEWLINE    '\\n'          (1, 9) (1, 10)
    COMMENT    '# NL'        (2, 4) (2, 8)
    NL         '\\n'          (2, 8) (2, 9)
    INDENT     '    '        (3, 0) (3, 4)
    NAME       'True'        (3, 4) (3, 8)
    OP         '='           (3, 9) (3, 10)
    NAME       'False'       (3, 11) (3, 16)
    COMMENT    '# NEWLINE'   (3, 17) (3, 26)
    NEWLINE    '\\n'          (3, 26) (3, 27)
    DEDENT     ''            (4, 0) (4, 0)
    """)

        indent_error_file = """\
def k(x):
    x += 2
  x += 5
"""
        with self.assertRaisesRegexp(IndentationError,
                                     "unindent does not match any "
                                     "outer indentation level"):
            for tok in generate_tokens(StringIO(indent_error_file).readline):
                pass

    def test_int(self):
        # Ordinary integers and binary operators
        self.check_tokenize("0xff <= 255", """\
    NUMBER     '0xff'        (1, 0) (1, 4)
    OP         '<='          (1, 5) (1, 7)
    NUMBER     '255'         (1, 8) (1, 11)
    """)
        self.check_tokenize("0b10 <= 255", """\
    NUMBER     '0b10'        (1, 0) (1, 4)
    OP         '<='          (1, 5) (1, 7)
    NUMBER     '255'         (1, 8) (1, 11)
    """)
        self.check_tokenize("0o123 <= 0123", """\
    NUMBER     '0o123'       (1, 0) (1, 5)
    OP         '<='          (1, 6) (1, 8)
    NUMBER     '0123'        (1, 9) (1, 13)
    """)
        self.check_tokenize("01234567 > ~0x15", """\
    NUMBER     '01234567'    (1, 0) (1, 8)
    OP         '>'           (1, 9) (1, 10)
    OP         '~'           (1, 11) (1, 12)
    NUMBER     '0x15'        (1, 12) (1, 16)
    """)
        self.check_tokenize("2134568 != 01231515", """\
    NUMBER     '2134568'     (1, 0) (1, 7)
    OP         '!='          (1, 8) (1, 10)
    NUMBER     '01231515'    (1, 11) (1, 19)
    """)
        self.check_tokenize("(-124561-1) & 0200000000", """\
    OP         '('           (1, 0) (1, 1)
    OP         '-'           (1, 1) (1, 2)
    NUMBER     '124561'      (1, 2) (1, 8)
    OP         '-'           (1, 8) (1, 9)
    NUMBER     '1'           (1, 9) (1, 10)
    OP         ')'           (1, 10) (1, 11)
    OP         '&'           (1, 12) (1, 13)
    NUMBER     '0200000000'  (1, 14) (1, 24)
    """)
        self.check_tokenize("0xdeadbeef != -1", """\
    NUMBER     '0xdeadbeef'  (1, 0) (1, 10)
    OP         '!='          (1, 11) (1, 13)
    OP         '-'           (1, 14) (1, 15)
    NUMBER     '1'           (1, 15) (1, 16)
    """)
        self.check_tokenize("0xdeadc0de & 012345", """\
    NUMBER     '0xdeadc0de'  (1, 0) (1, 10)
    OP         '&'           (1, 11) (1, 12)
    NUMBER     '012345'      (1, 13) (1, 19)
    """)
        self.check_tokenize("0xFF & 0x15 | 1234", """\
    NUMBER     '0xFF'        (1, 0) (1, 4)
    OP         '&'           (1, 5) (1, 6)
    NUMBER     '0x15'        (1, 7) (1, 11)
    OP         '|'           (1, 12) (1, 13)
    NUMBER     '1234'        (1, 14) (1, 18)
    """)

    def test_long(self):
        # Long integers
        self.check_tokenize("x = 0L", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '0L'          (1, 4) (1, 6)
    """)
        self.check_tokenize("x = 0xfffffffffff", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '0xffffffffff (1, 4) (1, 17)
    """)
        self.check_tokenize("x = 123141242151251616110l", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '123141242151 (1, 4) (1, 26)
    """)
        self.check_tokenize("x = -15921590215012591L", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    OP         '-'           (1, 4) (1, 5)
    NUMBER     '159215902150 (1, 5) (1, 23)
    """)

    def test_float(self):
        # Floating point numbers
        self.check_tokenize("x = 3.14159", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '3.14159'     (1, 4) (1, 11)
    """)
        self.check_tokenize("x = 314159.", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '314159.'     (1, 4) (1, 11)
    """)
        self.check_tokenize("x = .314159", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '.314159'     (1, 4) (1, 11)
    """)
        self.check_tokenize("x = 3e14159", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '3e14159'     (1, 4) (1, 11)
    """)
        self.check_tokenize("x = 3E123", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '3E123'       (1, 4) (1, 9)
    """)
        self.check_tokenize("x+y = 3e-1230", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '+'           (1, 1) (1, 2)
    NAME       'y'           (1, 2) (1, 3)
    OP         '='           (1, 4) (1, 5)
    NUMBER     '3e-1230'     (1, 6) (1, 13)
    """)
        self.check_tokenize("x = 3.14e159", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '3.14e159'    (1, 4) (1, 12)
    """)

    def test_string(self):
        # String literals
        self.check_tokenize("x = ''; y = \"\"", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    STRING     "''"          (1, 4) (1, 6)
    OP         ';'           (1, 6) (1, 7)
    NAME       'y'           (1, 8) (1, 9)
    OP         '='           (1, 10) (1, 11)
    STRING     '""'          (1, 12) (1, 14)
    """)
        self.check_tokenize("x = '\"'; y = \"'\"", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    STRING     '\\'"\\''       (1, 4) (1, 7)
    OP         ';'           (1, 7) (1, 8)
    NAME       'y'           (1, 9) (1, 10)
    OP         '='           (1, 11) (1, 12)
    STRING     '"\\'"'        (1, 13) (1, 16)
    """)
        self.check_tokenize("x = \"doesn't \"shrink\", does it\"", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    STRING     '"doesn\\'t "' (1, 4) (1, 14)
    NAME       'shrink'      (1, 14) (1, 20)
    STRING     '", does it"' (1, 20) (1, 31)
    """)
        self.check_tokenize("x = u'abc' + U'ABC'", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    STRING     "u'abc'"      (1, 4) (1, 10)
    OP         '+'           (1, 11) (1, 12)
    STRING     "U'ABC'"      (1, 13) (1, 19)
    """)
        self.check_tokenize('y = u"ABC" + U"ABC"', """\
    NAME       'y'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    STRING     'u"ABC"'      (1, 4) (1, 10)
    OP         '+'           (1, 11) (1, 12)
    STRING     'U"ABC"'      (1, 13) (1, 19)
    """)
        self.check_tokenize("x = ur'abc' + Ur'ABC' + uR'ABC' + UR'ABC'", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    STRING     "ur'abc'"     (1, 4) (1, 11)
    OP         '+'           (1, 12) (1, 13)
    STRING     "Ur'ABC'"     (1, 14) (1, 21)
    OP         '+'           (1, 22) (1, 23)
    STRING     "uR'ABC'"     (1, 24) (1, 31)
    OP         '+'           (1, 32) (1, 33)
    STRING     "UR'ABC'"     (1, 34) (1, 41)
    """)
        self.check_tokenize('y = ur"abc" + Ur"ABC" + uR"ABC" + UR"ABC"', """\
    NAME       'y'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    STRING     'ur"abc"'     (1, 4) (1, 11)
    OP         '+'           (1, 12) (1, 13)
    STRING     'Ur"ABC"'     (1, 14) (1, 21)
    OP         '+'           (1, 22) (1, 23)
    STRING     'uR"ABC"'     (1, 24) (1, 31)
    OP         '+'           (1, 32) (1, 33)
    STRING     'UR"ABC"'     (1, 34) (1, 41)

    """)
        self.check_tokenize("b'abc' + B'abc'", """\
    STRING     "b'abc'"      (1, 0) (1, 6)
    OP         '+'           (1, 7) (1, 8)
    STRING     "B'abc'"      (1, 9) (1, 15)
    """)
        self.check_tokenize('b"abc" + B"abc"', """\
    STRING     'b"abc"'      (1, 0) (1, 6)
    OP         '+'           (1, 7) (1, 8)
    STRING     'B"abc"'      (1, 9) (1, 15)
    """)
        self.check_tokenize("br'abc' + bR'abc' + Br'abc' + BR'abc'", """\
    STRING     "br'abc'"     (1, 0) (1, 7)
    OP         '+'           (1, 8) (1, 9)
    STRING     "bR'abc'"     (1, 10) (1, 17)
    OP         '+'           (1, 18) (1, 19)
    STRING     "Br'abc'"     (1, 20) (1, 27)
    OP         '+'           (1, 28) (1, 29)
    STRING     "BR'abc'"     (1, 30) (1, 37)
    """)
        self.check_tokenize('br"abc" + bR"abc" + Br"abc" + BR"abc"', """\
    STRING     'br"abc"'     (1, 0) (1, 7)
    OP         '+'           (1, 8) (1, 9)
    STRING     'bR"abc"'     (1, 10) (1, 17)
    OP         '+'           (1, 18) (1, 19)
    STRING     'Br"abc"'     (1, 20) (1, 27)
    OP         '+'           (1, 28) (1, 29)
    STRING     'BR"abc"'     (1, 30) (1, 37)
    """)

    def test_function(self):
        self.check_tokenize("def d22(a, b, c=2, d=2, *k): pass", """\
    NAME       'def'         (1, 0) (1, 3)
    NAME       'd22'         (1, 4) (1, 7)
    OP         '('           (1, 7) (1, 8)
    NAME       'a'           (1, 8) (1, 9)
    OP         ','           (1, 9) (1, 10)
    NAME       'b'           (1, 11) (1, 12)
    OP         ','           (1, 12) (1, 13)
    NAME       'c'           (1, 14) (1, 15)
    OP         '='           (1, 15) (1, 16)
    NUMBER     '2'           (1, 16) (1, 17)
    OP         ','           (1, 17) (1, 18)
    NAME       'd'           (1, 19) (1, 20)
    OP         '='           (1, 20) (1, 21)
    NUMBER     '2'           (1, 21) (1, 22)
    OP         ','           (1, 22) (1, 23)
    OP         '*'           (1, 24) (1, 25)
    NAME       'k'           (1, 25) (1, 26)
    OP         ')'           (1, 26) (1, 27)
    OP         ':'           (1, 27) (1, 28)
    NAME       'pass'        (1, 29) (1, 33)
    """)
        self.check_tokenize("def d01v_(a=1, *k, **w): pass", """\
    NAME       'def'         (1, 0) (1, 3)
    NAME       'd01v_'       (1, 4) (1, 9)
    OP         '('           (1, 9) (1, 10)
    NAME       'a'           (1, 10) (1, 11)
    OP         '='           (1, 11) (1, 12)
    NUMBER     '1'           (1, 12) (1, 13)
    OP         ','           (1, 13) (1, 14)
    OP         '*'           (1, 15) (1, 16)
    NAME       'k'           (1, 16) (1, 17)
    OP         ','           (1, 17) (1, 18)
    OP         '**'          (1, 19) (1, 21)
    NAME       'w'           (1, 21) (1, 22)
    OP         ')'           (1, 22) (1, 23)
    OP         ':'           (1, 23) (1, 24)
    NAME       'pass'        (1, 25) (1, 29)
    """)

    def test_comparison(self):
        # Comparison
        self.check_tokenize("if 1 < 1 > 1 == 1 >= 5 <= 0x15 <= 0x12 != " +
                            "1 and 5 in 1 not in 1 is 1 or 5 is not 1: pass", """\
    NAME       'if'          (1, 0) (1, 2)
    NUMBER     '1'           (1, 3) (1, 4)
    OP         '<'           (1, 5) (1, 6)
    NUMBER     '1'           (1, 7) (1, 8)
    OP         '>'           (1, 9) (1, 10)
    NUMBER     '1'           (1, 11) (1, 12)
    OP         '=='          (1, 13) (1, 15)
    NUMBER     '1'           (1, 16) (1, 17)
    OP         '>='          (1, 18) (1, 20)
    NUMBER     '5'           (1, 21) (1, 22)
    OP         '<='          (1, 23) (1, 25)
    NUMBER     '0x15'        (1, 26) (1, 30)
    OP         '<='          (1, 31) (1, 33)
    NUMBER     '0x12'        (1, 34) (1, 38)
    OP         '!='          (1, 39) (1, 41)
    NUMBER     '1'           (1, 42) (1, 43)
    NAME       'and'         (1, 44) (1, 47)
    NUMBER     '5'           (1, 48) (1, 49)
    NAME       'in'          (1, 50) (1, 52)
    NUMBER     '1'           (1, 53) (1, 54)
    NAME       'not'         (1, 55) (1, 58)
    NAME       'in'          (1, 59) (1, 61)
    NUMBER     '1'           (1, 62) (1, 63)
    NAME       'is'          (1, 64) (1, 66)
    NUMBER     '1'           (1, 67) (1, 68)
    NAME       'or'          (1, 69) (1, 71)
    NUMBER     '5'           (1, 72) (1, 73)
    NAME       'is'          (1, 74) (1, 76)
    NAME       'not'         (1, 77) (1, 80)
    NUMBER     '1'           (1, 81) (1, 82)
    OP         ':'           (1, 82) (1, 83)
    NAME       'pass'        (1, 84) (1, 88)
    """)

    def test_shift(self):
        # Shift
        self.check_tokenize("x = 1 << 1 >> 5", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '1'           (1, 4) (1, 5)
    OP         '<<'          (1, 6) (1, 8)
    NUMBER     '1'           (1, 9) (1, 10)
    OP         '>>'          (1, 11) (1, 13)
    NUMBER     '5'           (1, 14) (1, 15)
    """)

    def test_additive(self):
        # Additive
        self.check_tokenize("x = 1 - y + 15 - 01 + 0x124 + z + a[5]", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '1'           (1, 4) (1, 5)
    OP         '-'           (1, 6) (1, 7)
    NAME       'y'           (1, 8) (1, 9)
    OP         '+'           (1, 10) (1, 11)
    NUMBER     '15'          (1, 12) (1, 14)
    OP         '-'           (1, 15) (1, 16)
    NUMBER     '01'          (1, 17) (1, 19)
    OP         '+'           (1, 20) (1, 21)
    NUMBER     '0x124'       (1, 22) (1, 27)
    OP         '+'           (1, 28) (1, 29)
    NAME       'z'           (1, 30) (1, 31)
    OP         '+'           (1, 32) (1, 33)
    NAME       'a'           (1, 34) (1, 35)
    OP         '['           (1, 35) (1, 36)
    NUMBER     '5'           (1, 36) (1, 37)
    OP         ']'           (1, 37) (1, 38)
    """)

    def test_multiplicative(self):
        # Multiplicative
        self.check_tokenize("x = 1//1*1/5*12%0x12", """\
    NAME       'x'           (1, 0) (1, 1)
    OP         '='           (1, 2) (1, 3)
    NUMBER     '1'           (1, 4) (1, 5)
    OP         '//'          (1, 5) (1, 7)
    NUMBER     '1'           (1, 7) (1, 8)
    OP         '*'           (1, 8) (1, 9)
    NUMBER     '1'           (1, 9) (1, 10)
    OP         '/'           (1, 10) (1, 11)
    NUMBER     '5'           (1, 11) (1, 12)
    OP         '*'           (1, 12) (1, 13)
    NUMBER     '12'          (1, 13) (1, 15)
    OP         '%'           (1, 15) (1, 16)
    NUMBER     '0x12'        (1, 16) (1, 20)
    """)

    def test_unary(self):
        # Unary
        self.check_tokenize("~1 ^ 1 & 1 |1 ^ -1", """\
    OP         '~'           (1, 0) (1, 1)
    NUMBER     '1'           (1, 1) (1, 2)
    OP         '^'           (1, 3) (1, 4)
    NUMBER     '1'           (1, 5) (1, 6)
    OP         '&'           (1, 7) (1, 8)
    NUMBER     '1'           (1, 9) (1, 10)
    OP         '|'           (1, 11) (1, 12)
    NUMBER     '1'           (1, 12) (1, 13)
    OP         '^'           (1, 14) (1, 15)
    OP         '-'           (1, 16) (1, 17)
    NUMBER     '1'           (1, 17) (1, 18)
    """)
        self.check_tokenize("-1*1/1+1*1//1 - ---1**1", """\
    OP         '-'           (1, 0) (1, 1)
    NUMBER     '1'           (1, 1) (1, 2)
    OP         '*'           (1, 2) (1, 3)
    NUMBER     '1'           (1, 3) (1, 4)
    OP         '/'           (1, 4) (1, 5)
    NUMBER     '1'           (1, 5) (1, 6)
    OP         '+'           (1, 6) (1, 7)
    NUMBER     '1'           (1, 7) (1, 8)
    OP         '*'           (1, 8) (1, 9)
    NUMBER     '1'           (1, 9) (1, 10)
    OP         '//'          (1, 10) (1, 12)
    NUMBER     '1'           (1, 12) (1, 13)
    OP         '-'           (1, 14) (1, 15)
    OP         '-'           (1, 16) (1, 17)
    OP         '-'           (1, 17) (1, 18)
    OP         '-'           (1, 18) (1, 19)
    NUMBER     '1'           (1, 19) (1, 20)
    OP         '**'          (1, 20) (1, 22)
    NUMBER     '1'           (1, 22) (1, 23)
    """)

    def test_selector(self):
        # Selector
        self.check_tokenize("import sys, time\n"
                            "x = sys.modules['time'].time()", """\
    NAME       'import'      (1, 0) (1, 6)
    NAME       'sys'         (1, 7) (1, 10)
    OP         ','           (1, 10) (1, 11)
    NAME       'time'        (1, 12) (1, 16)
    NEWLINE    '\\n'          (1, 16) (1, 17)
    NAME       'x'           (2, 0) (2, 1)
    OP         '='           (2, 2) (2, 3)
    NAME       'sys'         (2, 4) (2, 7)
    OP         '.'           (2, 7) (2, 8)
    NAME       'modules'     (2, 8) (2, 15)
    OP         '['           (2, 15) (2, 16)
    STRING     "'time'"      (2, 16) (2, 22)
    OP         ']'           (2, 22) (2, 23)
    OP         '.'           (2, 23) (2, 24)
    NAME       'time'        (2, 24) (2, 28)
    OP         '('           (2, 28) (2, 29)
    OP         ')'           (2, 29) (2, 30)
    """)

    def test_method(self):
        # Methods
        self.check_tokenize("@staticmethod\n"
                            "def foo(x,y): pass", """\
    OP         '@'           (1, 0) (1, 1)
    NAME       'staticmethod (1, 1) (1, 13)
    NEWLINE    '\\n'          (1, 13) (1, 14)
    NAME       'def'         (2, 0) (2, 3)
    NAME       'foo'         (2, 4) (2, 7)
    OP         '('           (2, 7) (2, 8)
    NAME       'x'           (2, 8) (2, 9)
    OP         ','           (2, 9) (2, 10)
    NAME       'y'           (2, 10) (2, 11)
    OP         ')'           (2, 11) (2, 12)
    OP         ':'           (2, 12) (2, 13)
    NAME       'pass'        (2, 14) (2, 18)
    """)

    def test_tabs(self):
        # Evil tabs
        self.check_tokenize("def f():\n"
                            "\tif x\n"
                            "        \tpass", """\
    NAME       'def'         (1, 0) (1, 3)
    NAME       'f'           (1, 4) (1, 5)
    OP         '('           (1, 5) (1, 6)
    OP         ')'           (1, 6) (1, 7)
    OP         ':'           (1, 7) (1, 8)
    NEWLINE    '\\n'          (1, 8) (1, 9)
    INDENT     '\\t'          (2, 0) (2, 1)
    NAME       'if'          (2, 1) (2, 3)
    NAME       'x'           (2, 4) (2, 5)
    NEWLINE    '\\n'          (2, 5) (2, 6)
    INDENT     '        \\t'  (3, 0) (3, 9)
    NAME       'pass'        (3, 9) (3, 13)
    DEDENT     ''            (4, 0) (4, 0)
    DEDENT     ''            (4, 0) (4, 0)
    """)

    def test_pathological_trailing_whitespace(self):
        # Pathological whitespace (http://bugs.python.org/issue16152)
        self.check_tokenize("@          ", """\
    OP         '@'           (1, 0) (1, 1)
    """)


def decistmt(s):
    result = []
    g = generate_tokens(StringIO(s).readline)   # tokenize the string
    for toknum, tokval, _, _, _  in g:
        if toknum == NUMBER and '.' in tokval:  # replace NUMBER tokens
            result.extend([
                (NAME, 'Decimal'),
                (OP, '('),
                (STRING, repr(tokval)),
                (OP, ')')
            ])
        else:
            result.append((toknum, tokval))
    return untokenize(result)

class TestMisc(TestCase):

    def test_decistmt(self):
        # Substitute Decimals for floats in a string of statements.
        # This is an example from the docs.

        from decimal import Decimal
        s = '+21.3e-5*-.1234/81.7'
        self.assertEqual(decistmt(s),
                         "+Decimal ('21.3e-5')*-Decimal ('.1234')/Decimal ('81.7')")

        # The format of the exponent is inherited from the platform C library.
        # Known cases are "e-007" (Windows) and "e-07" (not Windows).  Since
        # we're only showing 12 digits, and the 13th isn't close to 5, the
        # rest of the output should be platform-independent.
        self.assertRegexpMatches(str(eval(s)), '-3.21716034272e-0+7')

        # Output from calculations with Decimal should be identical across all
        # platforms.
        self.assertEqual(eval(decistmt(s)), Decimal('-3.217160342717258261933904529E-7'))


class UntokenizeTest(TestCase):

    def test_bad_input_order(self):
        # raise if previous row
        u = Untokenizer()
        u.prev_row = 2
        u.prev_col = 2
        with self.assertRaises(ValueError) as cm:
            u.add_whitespace((1,3))
        self.assertEqual(cm.exception.args[0],
                'start (1,3) precedes previous end (2,2)')
        # raise if previous column in row
        self.assertRaises(ValueError, u.add_whitespace, (2,1))

    def test_backslash_continuation(self):
        # The problem is that <whitespace>\<newline> leaves no token
        u = Untokenizer()
        u.prev_row = 1
        u.prev_col =  1
        u.tokens = []
        u.add_whitespace((2, 0))
        self.assertEqual(u.tokens, ['\\\n'])
        u.prev_row = 2
        u.add_whitespace((4, 4))
        self.assertEqual(u.tokens, ['\\\n', '\\\n\\\n', '    '])

    def test_iter_compat(self):
        u = Untokenizer()
        token = (NAME, 'Hello')
        u.compat(token, iter([]))
        self.assertEqual(u.tokens, ["Hello "])
        u = Untokenizer()
        self.assertEqual(u.untokenize(iter([token])), 'Hello ')


class TestRoundtrip(TestCase):

    def check_roundtrip(self, f):
        """
        Test roundtrip for `untokenize`. `f` is an open file or a string.
        The source code in f is tokenized, converted back to source code
        via tokenize.untokenize(), and tokenized again from the latter.
        The test fails if the second tokenization doesn't match the first.
        """
        if isinstance(f, str): f = StringIO(f)
        token_list = list(generate_tokens(f.readline))
        f.close()
        tokens1 = [tok[:2] for tok in token_list]
        new_text = untokenize(tokens1)
        readline = iter(new_text.splitlines(1)).next
        tokens2 = [tok[:2] for tok in generate_tokens(readline)]
        self.assertEqual(tokens2, tokens1)

    def test_roundtrip(self):
        # There are some standard formatting practices that are easy to get right.

        self.check_roundtrip("if x == 1:\n"
                             "    print(x)\n")

        # There are some standard formatting practices that are easy to get right.

        self.check_roundtrip("if x == 1:\n"
                             "    print x\n")
        self.check_roundtrip("# This is a comment\n"
                             "# This also")

        # Some people use different formatting conventions, which makes
        # untokenize a little trickier. Note that this test involves trailing
        # whitespace after the colon. Note that we use hex escapes to make the
        # two trailing blanks apperant in the expected output.

        self.check_roundtrip("if x == 1 : \n"
                             "  print x\n")
        fn = test_support.findfile("tokenize_tests" + os.extsep + "txt")
        with open(fn) as f:
            self.check_roundtrip(f)
        self.check_roundtrip("if x == 1:\n"
                             "    # A comment by itself.\n"
                             "    print x # Comment here, too.\n"
                             "    # Another comment.\n"
                             "after_if = True\n")
        self.check_roundtrip("if (x # The comments need to go in the right place\n"
                             "    == 1):\n"
                             "    print 'x==1'\n")
        self.check_roundtrip("class Test: # A comment here\n"
                             "  # A comment with weird indent\n"
                             "  after_com = 5\n"
                             "  def x(m): return m*5 # a one liner\n"
                             "  def y(m): # A whitespace after the colon\n"
                             "     return y*4 # 3-space indent\n")

        # Some error-handling code

        self.check_roundtrip("try: import somemodule\n"
                             "except ImportError: # comment\n"
                             "    print 'Can not import' # comment2\n"
                             "else:   print 'Loaded'\n")

    def test_continuation(self):
        # Balancing continuation
        self.check_roundtrip("a = (3,4, \n"
                             "5,6)\n"
                             "y = [3, 4,\n"
                             "5]\n"
                             "z = {'a': 5,\n"
                             "'b':15, 'c':True}\n"
                             "x = len(y) + 5 - a[\n"
                             "3] - a[2]\n"
                             "+ len(z) - z[\n"
                             "'b']\n")

    def test_backslash_continuation(self):
        # Backslash means line continuation, except for comments
        self.check_roundtrip("x=1+\\\n"
                             "1\n"
                             "# This is a comment\\\n"
                             "# This also\n")
        self.check_roundtrip("# Comment \\\n"
                             "x = 0")

    def test_string_concatenation(self):
        # Two string literals on the same line
        self.check_roundtrip("'' ''")

    def test_random_files(self):
        # Test roundtrip on random python modules.
        # pass the '-ucpu' option to process the full directory.

        import glob, random
        fn = test_support.findfile("tokenize_tests" + os.extsep + "txt")
        tempdir = os.path.dirname(fn) or os.curdir
        testfiles = glob.glob(os.path.join(tempdir, "test*.py"))

        if not test_support.is_resource_enabled("cpu"):
            testfiles = random.sample(testfiles, 10)

        for testfile in testfiles:
            try:
                with open(testfile, 'rb') as f:
                    self.check_roundtrip(f)
            except:
                print "Roundtrip failed for file %s" % testfile
                raise


    def roundtrip(self, code):
        if isinstance(code, str):
            code = code.encode('utf-8')
        tokens = generate_tokens(StringIO(code).readline)
        return untokenize(tokens).decode('utf-8')

    def test_indentation_semantics_retained(self):
        """
        Ensure that although whitespace might be mutated in a roundtrip,
        the semantic meaning of the indentation remains consistent.
        """
        code = "if False:\n\tx=3\n\tx=3\n"
        codelines = self.roundtrip(code).split('\n')
        self.assertEqual(codelines[1], codelines[2])


def test_main():
    test_support.run_unittest(TokenizeTest)
    test_support.run_unittest(UntokenizeTest)
    test_support.run_unittest(TestRoundtrip)
    test_support.run_unittest(TestMisc)

if __name__ == "__main__":
    test_main()