with Debugger():
remove_html_markup('abc')
if __name__ == "__main__":
# ignore
assert not next_inputs()
if __package__ is None or __package__ == "":
from bookutils import quiz
else:
from .bookutils import quiz
if __name__ == "__main__":
quiz("What happens if we enter 'break 2 + 3'?", [
"A breakpoint is set in Line 2.", "A breakpoint is set in Line 5.",
"Two breakpoints are set in Lines 2 and 3.",
"The debugger raises a ValueError exception."
], 12345 % 7)
# ## Deleting Breakpoints
if __name__ == "__main__":
print('\n## Deleting Breakpoints')
class Debugger(Debugger):
def delete_command(self, arg=""):
"""Delete breakoint in given line. Without given line, clear all breakpoints"""
if arg:
try:
self.breakpoints.remove(int(arg))
if __name__ == "__main__":
for i, html in enumerate(['<b>foo</b>',
'<b>"foo"</b>',
'"<b>foo</b>"',
'<"b">foo</"b">']):
result = remove_html_markup(html)
print("%-2d %-15s %s" % (i + 1, html, result))
if __name__ == "__main__":
quiz("From the difference between success and failure,"
" we can already devise some observations about "
" what's wrong with the output."
" Which of these can we turn into general hypotheses?",
["Double quotes are stripped from the tagged input.",
"Tags in double quotes are not stripped.",
"The tag '<b>' is always stripped from the input.",
"Four-letter words are stripped."], [298 % 33, 1234 % 616])
# ### Testing a Hypothesis
if __name__ == "__main__":
print('\n### Testing a Hypothesis')
if __name__ == "__main__":
remove_html_markup('"foo"')
sys.settrace(None)
return ret
if __name__ == "__main__":
remove_html_markup_traced('xyz')
import math
if __name__ == "__main__":
quiz(
"What happens if the tracing function returns None"
" while tracing function f()?"
" Lookup sys.setttrace() in the Python documentation"
" or try it out yourself.", [
'Tracing stops for all functions;'
' the tracing function is no longer called',
'Tracing stops for f(): the tracing function is called when f() returns',
'Tracing stops for f() the rest of the execution: the tracing function'
' is no longer called for calls to f()', 'Nothing changes'
], math.log(7.38905609893065))
# ## A Tracer Class
if __name__ == "__main__":
print('\n## A Tracer Class')
class Tracer(object):
def __init__(self, file=sys.stdout):
"""Trace a block of code, sending logs to file (default: stdout)"""
if __name__ == "__main__":
with DeltaDebugger() as dd:
mystery(failing_input)
if __name__ == "__main__":
dd.args()
if __name__ == "__main__":
dd.min_args()
if __name__ == "__main__":
quiz(
"What happens if the function under test does not raise an exception?",
[
"Delta debugging searches for the minimal input"
" that produces the same result",
"Delta debugging starts a fuzzer to find an exception",
"Delta debugging raises an exception"
"Delta debugging runs forever in a loop",
], 0**0 + 1**0 + 0**1 + 1**1)
if __name__ == "__main__":
with ExpectError(NotFailingError):
with DeltaDebugger() as dd:
mystery("An input that does not fail")
# ## Usage Examples
if __name__ == "__main__":
print('\n## Usage Examples')
all_notebooks = [
node for node in change_counter.changes.keys()
if len(node) == 2 and node[1].endswith('.ipynb')
]
all_notebooks.sort(key=lambda node: change_counter.changes[node],
reverse=True)
if __package__ is None or __package__ == "":
from bookutils import quiz
else:
from .bookutils import quiz
if __name__ == "__main__":
quiz("Which two notebooks have seen the most changes over time?", [
f"`{all_notebooks[3][1].split('.')[0]}`",
f"`{all_notebooks[1][1].split('.')[0]}`",
f"`{all_notebooks[2][1].split('.')[0]}`",
f"`{all_notebooks[0][1].split('.')[0]}`",
], [1234 % 3, 3702 / 1234])
if __name__ == "__main__":
all_notebooks[0][1].split('.')[0], all_notebooks[1][1].split('.')[0]
# ## Past Fixes
if __name__ == "__main__":
print('\n## Past Fixes')
class FixCounter(ChangeCounter):
def include(self, m):
"""Include all modifications whose commit messages start with 'Fix:'"""
if __name__ == "__main__":
import os
os.system(f'python -O -c \'assert 2 + 2 == 5; print("Foo")\'')
def fun():
assert 2 + 2 == 5
if __name__ == "__main__":
quiz("If we invoke `fun()` and the assertion fails,"
" which information do we get?",
[
"The failing condition (`2 + 2 == 5`)",
"The location of the assertion in the program",
"The list of callers",
"All of the above"
],
123456789 % 5
)
if __name__ == "__main__":
with ExpectError():
fun()
# ## Checking Preconditions
if __name__ == "__main__":
print('\n## Checking Preconditions')
if __name__ == "__main__":
assert patch(version_1, []) == version_1
if __name__ == "__main__":
print(patch_string(patches[0]))
if __name__ == "__main__":
print_content(patch(version_1, [patches[0]]))
if __name__ == "__main__":
print_content(patch(version_1, [patches[1]]))
if __name__ == "__main__":
quiz("What has changed in version 1 after applying the second patch?", [
"The initialization of quote is deleted",
"The condition after `if c == '<'` is expanded",
"The tag variable gets a different value", "None of the above"
], 1 / 1 + 1**1 - 1 % 1 * 1)
# ## Delta Debugging on Patches
if __name__ == "__main__":
print('\n## Delta Debugging on Patches')
def test_remove_html_markup(patches):
new_version = patch(version_1, patches)
exec(new_version, globals())
assert remove_html_markup('"foo"') == '"foo"'
print(f"{line_number:4} {marker} {line}", end='')
line_number += 1
if __name__ == "__main__":
list_with_coverage(remove_html_markup, c.coverage)
if __package__ is None or __package__ == "":
from bookutils import quiz
else:
from .bookutils import quiz
if __name__ == "__main__":
quiz(
"Let the input be <code>"<b>Don't do this!</b>"</code>. "
"Which of these lines are executed? Use the code to find out!", [
"<code>tag = True</code>", "<code>tag = False</code>",
"<code>quote = not quote</code>", "<code>out = out + c</code>"
], [ord(c) - ord('a') - 1 for c in 'cdf'])
if __name__ == "__main__":
with CoverageCollector() as c:
remove_html_markup("<b>Don't do this!</b>")
# list_with_coverage(remove_html_markup, c.coverage)
# ## Computing Differences
if __name__ == "__main__":
print('\n## Computing Differences')
# ### A Base Class for Statistical Debugging
print(f"{line_number:4} {marker} {line}", end='')
line_number += 1
if __name__ == "__main__":
code_with_coverage(remove_html_markup, c.coverage())
if __package__ is None or __package__ == "":
from bookutils import quiz
else:
from .bookutils import quiz
if __name__ == "__main__":
quiz(
'Let the input be `"<b>Don\'t do this!</b>"`. '
"Which of these lines are executed? Use the code to find out!", [
"`tag = True`", "`tag = False`", "`quote = not quote`",
"`out = out + c`"
], [ord(c) - ord('a') - 1 for c in 'cdf'])
if __name__ == "__main__":
with CoverageCollector() as c:
remove_html_markup("<b>Don't do this!</b>")
# code_with_coverage(remove_html_markup, c.coverage)
# ## Computing Differences
if __name__ == "__main__":
print('\n## Computing Differences')
# ### A Base Class for Statistical Debugging
os.system(f'python -c \'assert 2 + 2 == 5; print("Foo")\'')
if __name__ == "__main__":
import os
os.system(f'python -O -c \'assert 2 + 2 == 5; print("Foo")\'')
def fun():
assert 2 + 2 == 5
if __name__ == "__main__":
quiz(
"If we invoke fun() and the assertion fails,"
" which information do we get?", [
"The failing condition (2 + 2 == 5)",
"The location of the assertion in the program",
"The list of callers", "All of the above"
], 123456789 % 5)
if __name__ == "__main__":
with ExpectError():
fun()
# ## Checking Preconditions
if __name__ == "__main__":
print('\n## Checking Preconditions')
def square_root(x):
with ExpectError():
square_root_with_checked_type_annotations(True)
if __name__ == "__main__":
square_root(True)
if __package__ is None or __package__ == "":
from bookutils import quiz
else:
from .bookutils import quiz
if __name__ == "__main__":
quiz(
"What happens if we call "
"`square_root_with_checked_type_annotations(1)`?", [
"`1` is automatically converted to float. It will pass.",
"`1` is a subtype of float. It will pass.",
"`1` is an integer, and no float. The type check will fail.",
"The function will fail for some other reason."
], 1)
if __name__ == "__main__":
with ExpectError(enforce.exceptions.RuntimeTypeError):
square_root_with_checked_type_annotations(1)
from typing import Union, Optional
@enforce.runtime_validation
def square_root_with_union_type(x: Union[int, float]) -> float:
"""Computes the square root of x, using the Newton-Raphson method"""
return square_root(x)
