Parsing docstrings

This module contains functions and classes that parse docstrings.

AUTHORS:

  • David Roe (2012-03-27) – initial version, based on Robert Bradshaw’s code.
class sage.doctest.parsing.MarkedOutput

Bases: str

A subclass of string with context for whether another string matches it.

EXAMPLES:

sage: from sage.doctest.parsing import MarkedOutput
sage: s = MarkedOutput("abc")
sage: s.rel_tol
0
sage: s.update(rel_tol = .05)
'abc'
sage: s.rel_tol
0.0500000000000000
update(**kwds)

EXAMPLES:

sage: from sage.doctest.parsing import MarkedOutput
sage: s = MarkedOutput("0.0007401")
sage: s.update(abs_tol = .0000001)
'0.0007401'
sage: s.rel_tol
0
sage: s.abs_tol
1.00000000000000e-7
class sage.doctest.parsing.OriginalSource(example)

Context swapping out the pre-parsed source with the original for better reporting.

EXAMPLES:

sage: from sage.doctest.sources import FileDocTestSource
sage: from sage.doctest.control import DocTestDefaults
sage: from sage.env import SAGE_SRC
sage: import os
sage: filename = os.path.join(SAGE_SRC,'sage','doctest','forker.py')
sage: FDS = FileDocTestSource(filename,DocTestDefaults())
sage: doctests, extras = FDS.create_doctests(globals())
sage: ex = doctests[0].examples[0]
sage: ex.sage_source
'doctest_var = 42; doctest_var^2\n'
sage: ex.source
'doctest_var = Integer(42); doctest_var**Integer(2)\n'
sage: from sage.doctest.parsing import OriginalSource
sage: with OriginalSource(ex):
...       ex.source
'doctest_var = 42; doctest_var^2\n'
class sage.doctest.parsing.SageDocTestParser(long=False, optional_tags=())

Bases: doctest.DocTestParser

A version of the standard doctest parser which handles Sage’s custom options and tolerances in floating point arithmetic.

parse(string, *args)

A Sage specialization of doctest.DocTestParser.

INPUTS:

  • string – the string to parse.
  • name – optional string giving the name indentifying string, to be used in error messages.

OUTPUTS:

  • A list consisting of strings and doctest.Example instances. There will be at least one string between successive examples (exactly one unless or long or optional tests are removed), and it will begin and end with a string.

EXAMPLES:

sage: from sage.doctest.parsing import SageDocTestParser
sage: DTP = SageDocTestParser(True, ('sage','magma','guava'))
sage: example = 'Explanatory text::\n\n    sage: E = magma("EllipticCurve([1, 1, 1, -10, -10])") # optional: magma\n\nLater text'
sage: parsed = DTP.parse(example)
sage: parsed[0]
'Explanatory text::\n\n'
sage: parsed[1].sage_source
'E = magma("EllipticCurve([1, 1, 1, -10, -10])") # optional: magma\n'
sage: parsed[2]
'\nLater text'

If the doctest parser is not created to accept a given optional argument, the corresponding examples will just be removed:

sage: DTP2 = SageDocTestParser(True, ('sage',))
sage: parsed2 = DTP2.parse(example)
sage: parsed2
['Explanatory text::\n\n', '\nLater text']

You can mark doctests as having a particular tolerance:

sage: example2 = 'sage: gamma(1.6) # tol 2.0e-11\n0.893515349287690'
sage: ex = DTP.parse(example2)[1]
sage: ex.sage_source
'gamma(1.6) # tol 2.0e-11\n'
sage: ex.want
'0.893515349287690\n'
sage: type(ex.want)
<class 'sage.doctest.parsing.MarkedOutput'>
sage: ex.want.tol
2e-11

You can use continuation lines:

sage: s = “sage: for i in range(4):n....: print in....:n” sage: ex = DTP2.parse(s)[1] sage: ex.source ‘for i in range(Integer(4)):n print in’

Sage currently accepts backslashes as indicating that the end of the current line should be joined to the next line. This feature allows for breaking large integers over multiple lines but is not standard for Python doctesting. It’s not guaranteed to persist, but works in Sage 5.5:

sage: n = 1234\
....:     5678
sage: print n
12345678
sage: type(n)
<type 'sage.rings.integer.Integer'>

It also works without the line continuation:

sage: m = 8765\
4321
sage: print m
87654321
class sage.doctest.parsing.SageOutputChecker

Bases: doctest.OutputChecker

A modification of the doctest OutputChecker that can check relative and absolute tolerance of answers.

EXAMPLES:

sage: from sage.doctest.parsing import SageOutputChecker, MarkedOutput, SageDocTestParser
sage: import doctest
sage: optflag = doctest.NORMALIZE_WHITESPACE|doctest.ELLIPSIS
sage: DTP = SageDocTestParser(True, ('sage','magma','guava'))
sage: OC = SageOutputChecker()
sage: example2 = 'sage: gamma(1.6) # tol 2.0e-11\n0.893515349287690'
sage: ex = DTP.parse(example2)[1]
sage: ex.sage_source
'gamma(1.6) # tol 2.0e-11\n'
sage: ex.want
'0.893515349287690\n'
sage: type(ex.want)
<class 'sage.doctest.parsing.MarkedOutput'>
sage: ex.want.tol
2e-11
sage: OC.check_output(ex.want, '0.893515349287690', optflag)
True
sage: OC.check_output(ex.want, '0.8935153492877', optflag)
True
sage: OC.check_output(ex.want, '0', optflag)
False
sage: OC.check_output(ex.want, 'x + 0.8935153492877', optflag)
False
check_output(want, got, optionflags)

Checks to see if the output matches the desired output.

If want is a MarkedOutput instance, takes into account the desired tolerance.

INPUT:

OUTPUT:

  • boolean, whether got matches want up to the specified tolerance.

EXAMPLES:

sage: from sage.doctest.parsing import MarkedOutput, SageOutputChecker
sage: import doctest
sage: optflag = doctest.NORMALIZE_WHITESPACE|doctest.ELLIPSIS
sage: rndstr = MarkedOutput("I'm wrong!").update(random=True)
sage: tentol = MarkedOutput("10.0").update(tol=.1)
sage: tenabs = MarkedOutput("10.0").update(abs_tol=.1)
sage: tenrel = MarkedOutput("10.0").update(rel_tol=.1)
sage: zerotol = MarkedOutput("0.0").update(tol=.1)
sage: zeroabs = MarkedOutput("0.0").update(abs_tol=.1)
sage: zerorel = MarkedOutput("0.0").update(rel_tol=.1)
sage: zero = "0.0"
sage: nf = "9.5"
sage: ten = "10.05"
sage: eps = "-0.05"
sage: OC = SageOutputChecker()
sage: OC.check_output(rndstr,nf,optflag)
True

sage: OC.check_output(tentol,nf,optflag)
True
sage: OC.check_output(tentol,ten,optflag)
True
sage: OC.check_output(tentol,zero,optflag)
False

sage: OC.check_output(tenabs,nf,optflag)
False
sage: OC.check_output(tenabs,ten,optflag)
True
sage: OC.check_output(tenabs,zero,optflag)
False

sage: OC.check_output(tenrel,nf,optflag)
True
sage: OC.check_output(tenrel,ten,optflag)
True
sage: OC.check_output(tenrel,zero,optflag)
False

sage: OC.check_output(zerotol,zero,optflag)
True
sage: OC.check_output(zerotol,eps,optflag)
True
sage: OC.check_output(zerotol,ten,optflag)
False

sage: OC.check_output(zeroabs,zero,optflag)
True
sage: OC.check_output(zeroabs,eps,optflag)
True
sage: OC.check_output(zeroabs,ten,optflag)
False

sage: OC.check_output(zerorel,zero,optflag)
True
sage: OC.check_output(zerorel,eps,optflag)
False
sage: OC.check_output(zerorel,ten,optflag)
False

TESTS:

More explicit tolerance checks:

sage: _ = x  # rel tol 1e10
sage: raise RuntimeError   # rel tol 1e10
Traceback (most recent call last):
...
RuntimeError
sage: 1  # abs tol 2
-0.5
sage: print "1.000009"   # abs tol 1e-5
1.0
human_readable_escape_sequences(string)

Make ANSI escape sequences human readable.

EXAMPLES:

sage: print 'This is \x1b[1mbold\x1b[0m text'
This is <CSI-1m>bold<CSI-0m> text

TESTS:

sage: from sage.doctest.parsing import SageOutputChecker
sage: OC = SageOutputChecker()
sage: teststr = '-'.join([
....:     'bold\x1b[1m',
....:     'red\x1b[31m',
....:     'oscmd\x1ba'])
sage: OC.human_readable_escape_sequences(teststr)
'bold<CSI-1m>-red<CSI-31m>-oscmd<ESC-a>'
output_difference(example, got, optionflags)

Report on the differences between the desired result and what was actually obtained.

If want is a MarkedOutput instance, takes into account the desired tolerance.

INPUT:

OUTPUT:

  • a string, describing how got fails to match example.want

EXAMPLES:

sage: from sage.doctest.parsing import MarkedOutput, SageOutputChecker
sage: import doctest
sage: optflag = doctest.NORMALIZE_WHITESPACE|doctest.ELLIPSIS
sage: tentol = doctest.Example('',MarkedOutput("10.0\n").update(tol=.1))
sage: tenabs = doctest.Example('',MarkedOutput("10.0\n").update(abs_tol=.1))
sage: tenrel = doctest.Example('',MarkedOutput("10.0\n").update(rel_tol=.1))
sage: zerotol = doctest.Example('',MarkedOutput("0.0\n").update(tol=.1))
sage: zeroabs = doctest.Example('',MarkedOutput("0.0\n").update(abs_tol=.1))
sage: zerorel = doctest.Example('',MarkedOutput("0.0\n").update(rel_tol=.1))
sage: tlist = doctest.Example('',MarkedOutput("[10.0, 10.0, 10.0, 10.0, 10.0, 10.0]\n").update(abs_tol=1.0))
sage: zero = "0.0"
sage: nf = "9.5"
sage: ten = "10.05"
sage: eps = "-0.05"
sage: L = "[9.9, 8.7, 10.3, 11.2, 10.8, 10.0]"
sage: OC = SageOutputChecker()
sage: print OC.output_difference(tenabs,nf,optflag)
Expected:
    10.0
Got:
    9.5
Tolerance exceeded: 5e-01 > 1e-01

sage: print OC.output_difference(tentol,zero,optflag)
Expected:
    10.0
Got:
    0.0
Tolerance exceeded: infinity > 1e-01

sage: print OC.output_difference(tentol,eps,optflag)
Expected:
    10.0
Got:
    -0.05
Tolerance exceeded: 1e+00 > 1e-01

sage: print OC.output_difference(tlist,L,optflag)
Expected:
    [10.0, 10.0, 10.0, 10.0, 10.0, 10.0]
Got:
    [9.9, 8.7, 10.3, 11.2, 10.8, 10.0]
Tolerance exceeded in 2 of 6
    10.0 vs 8.7
    10.0 vs 11.2

TESTS:

sage: print OC.output_difference(tenabs,zero,optflag)
Expected:
    10.0
Got:
    0.0
Tolerance exceeded: 1e+01 > 1e-01

sage: print OC.output_difference(tenrel,zero,optflag)
Expected:
    10.0
Got:
    0.0
Tolerance exceeded: 1e+00 > 1e-01

sage: print OC.output_difference(tenrel,eps,optflag)
Expected:
    10.0
Got:
    -0.05
Tolerance exceeded: 1e+00 > 1e-01

sage: print OC.output_difference(zerotol,ten,optflag)
Expected:
    0.0
Got:
    10.05
Tolerance exceeded: 1e+01 > 1e-01

sage: print OC.output_difference(zeroabs,ten,optflag)
Expected:
    0.0
Got:
    10.05
Tolerance exceeded: 1e+01 > 1e-01

sage: print OC.output_difference(zerorel,eps,optflag)
Expected:
    0.0
Got:
    -0.05
Tolerance exceeded: infinity > 1e-01

sage: print OC.output_difference(zerorel,ten,optflag)
Expected:
    0.0
Got:
    10.05
Tolerance exceeded: infinity > 1e-01
sage.doctest.parsing.get_source(example)

Returns the source with the leading ‘sage: ‘ stripped off.

EXAMPLES:

sage: from sage.doctest.parsing import get_source
sage: from sage.doctest.sources import DictAsObject
sage: example = DictAsObject({})
sage: example.sage_source = "2 + 2"
sage: example.source = "sage: 2 + 2"
sage: get_source(example)
'2 + 2'
sage: example = DictAsObject({})
sage: example.source = "3 + 3"
sage: get_source(example)
'3 + 3'
sage.doctest.parsing.make_marked_output(s, D)

Auxilliary function for pickling.

EXAMPLES:

sage: from sage.doctest.parsing import make_marked_output
sage: s = make_marked_output("0.0007401",{'abs_tol':.0000001})
sage: s
'0.0007401'
sage: s.abs_tol
1.00000000000000e-7
sage.doctest.parsing.parse_optional_tags(string)

Returns a set consisting of the optional tags from the following set that occur in a comment on the first line of the input string.

  • ‘long time’
  • ‘not implemented’
  • ‘not tested’
  • ‘known bug’
  • ‘optional: PKG_NAME’ – the set will just contain ‘PKG_NAME’

EXAMPLES:

sage: from sage.doctest.parsing import parse_optional_tags
sage: parse_optional_tags("sage: magma('2 + 2')# optional: magma")
set(['magma'])
sage: parse_optional_tags("sage: #optional -- mypkg")
set(['mypkg'])
sage: parse_optional_tags("sage: print(1)  # parentheses are optional here")
set([])
sage: parse_optional_tags("sage: print(1)  # optional")
set([''])
sage: sorted(list(parse_optional_tags("sage: #optional -- foo bar, baz")))
['bar', 'foo']
sage: sorted(list(parse_optional_tags("    sage: factor(10^(10^10) + 1) # LoNg TiME, NoT TeSTED; OptioNAL -- P4cka9e")))
['long time', 'not tested', 'p4cka9e']
sage: parse_optional_tags("    sage: raise RuntimeError # known bug")
set(['bug'])
sage: sorted(list(parse_optional_tags("    sage: determine_meaning_of_life() # long time, not implemented")))
['long time', 'not implemented']

We don’t parse inside strings:

sage: parse_optional_tags("    sage: print '  # long time'")
set([])
sage: parse_optional_tags("    sage: print '  # long time'  # not tested")
set(['not tested'])

UTF-8 works:

sage: parse_optional_tags("'ěščřžýáíéďĎ'")
set([])
sage.doctest.parsing.parse_tolerance(source, want)

Returns a version of want marked up with the tolerance tags specified in source.

INPUT:

  • source – a string, the source of a doctest
  • want – a string, the desired output of the doctest

OUTPUT:

  • want if there are no tolerance tags specified; a MarkedOutput version otherwise.

EXAMPLES:

sage: from sage.doctest.parsing import parse_tolerance
sage: marked = parse_tolerance("sage: s.update(abs_tol = .0000001)", "")
sage: type(marked)
<type 'str'>
sage: marked = parse_tolerance("sage: s.update(tol = 0.1); s.rel_tol # abs tol 0.01", "")
sage: marked.tol
0
sage: marked.rel_tol
0
sage: marked.abs_tol
0.01
sage.doctest.parsing.pre_hash(s)

Prepends a string with its length.

EXAMPLES:

sage: from sage.doctest.parsing import pre_hash
sage: pre_hash("abc")
'3:abc'
sage.doctest.parsing.reduce_hex(fingerprints)

Returns a symmetric function of the arguments as hex strings.

The arguments should be 32 character strings consiting of hex digits: 0-9 and a-f.

EXAMPLES:

sage: from sage.doctest.parsing import reduce_hex
sage: reduce_hex(["abc", "12399aedf"])
'0000000000000000000000012399a463'
sage: reduce_hex(["12399aedf","abc"])
'0000000000000000000000012399a463'

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