* bpo-15987: Implement ast.compare
Add a compare() function that compares two ASTs for structural equality. There are two set of attributes on AST node objects, fields and attributes. The fields are always compared, since they represent the actual structure of the code. The attributes can be optionally be included in the comparison. Attributes capture things like line numbers of column offsets, so comparing them involves test whether the layout of the program text is the same. Since whitespace seems inessential for comparing ASTs, the default is to compare fields but not attributes.
ASTs are just Python objects that can be modified in arbitrary ways. The API for ASTs is under-specified in the presence of user modifications to objects. The comparison respects modifications to fields and attributes, and to _fields and _attributes attributes. A user could create obviously malformed objects, and the code will probably fail with an AttributeError when that happens. (For example, adding "spam" to _fields but not adding a "spam" attribute to the object.)
Co-authored-by: Jeremy Hylton <jeremy@alum.mit.edu>
The PEP 649 implementation will require a way to load NotImplementedError
from the bytecode. @markshannon suggested implementing this by converting
LOAD_ASSERTION_ERROR into a more general mechanism for loading constants.
This PR adds this new opcode. I will work on the rest of the implementation
of the PEP separately.
Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Co-authored-by: Erlend E. Aasland <erlend@python.org>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
* expand on What's New entry for PEP 667 (including porting notes)
* define 'optimized scope' as a glossary term
* cover comprehensions and generator expressions in locals() docs
* review all mentions of "locals" in documentation (updating if needed)
* review all mentions of "f_locals" in documentation (updating if needed)
regrtest test runner: Add XML support to the refleak checker
(-R option).
* run_unittest() now stores XML elements as string, rather than
objects, in support.junit_xml_list.
* runtest_refleak() now saves/restores XML strings before/after
checking for reference leaks. Save XML into a temporary file.
* Remove description of issue fixed in 3.5 from autospeccing guide
* Make autospeccing note text more succint and lint whitespace
* Add linting changes (missed in last commit)
---------
Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
* Fix for email.generator.Generator with whitespace between encoded words.
email.generator.Generator currently does not handle whitespace between
encoded words correctly when the encoded words span multiple lines. The
current generator will create an encoded word for each line. If the end
of the line happens to correspond with the end real word in the
plaintext, the generator will place an unencoded space at the start of
the subsequent lines to represent the whitespace between the plaintext
words.
A compliant decoder will strip all the whitespace from between two
encoded words which leads to missing spaces in the round-tripped
output.
The fix for this is to make sure that whitespace between two encoded
words ends up inside of one or the other of the encoded words. This
fix places the space inside of the second encoded word.
A second problem happens with continuation lines. A continuation line that
starts with whitespace and is followed by a non-encoded word is fine because
the newline between such continuation lines is defined as condensing to
a single space character. When the continuation line starts with whitespace
followed by an encoded word, however, the RFCs specify that the word is run
together with the encoded word on the previous line. This is because normal
words are filded on syntactic breaks by encoded words are not.
The solution to this is to add the whitespace to the start of the encoded word
on the continuation line.
Test cases are from #92081
* Rename a variable so it's not confused with the final variable.
Many users think they want a locals argument for various reasons but they do not
understand that it makes code be treated as a class definition. They do not want
their code treated as a class definition and get surprised. The reason not
to pass locals specifically is that the following code raises a `NameError`:
```py
exec("""
def f():
print("hi")
f()
def g():
f()
g()
""", {}, {})
```
The reason not to leave out globals is as follows:
```py
def t():
exec("""
def f():
print("hi")
f()
def g():
f()
g()
""")
```
Jelle Zijlstra
Eugene Triguba
Lysandros Nikolaou
Batuhan Taskaya
Landon Wood
Koudai Aono
Pablo Galindo Salgado
Brett Simmers
Irit Katriel
Nice Zombies
Victor Stinner
Josh Cannon
Serhiy Storchaka
Xie Yanbo
Arnon Yaari
Yan Yanchii
Blaise Pabon
Daniel Williams
Alastair Stanley
Savannah Ostrowski
Donghee Na
Nikita Sobolev
Alyssa Coghlan
Wulian233
Melanie Arbor
Alex Waygood
Shantanu
Mark Jason Dominus (陶敏修)
Shauna
Hugo van Kemenade
Tialo
Toshio Kuratomi
Daniel Hollas
Hood Chatham
Seth Michael Larson
Jeremy Hylton
Erlend E. Aasland
Sebastian Rittau