FM / pgen2

/usr/lib64/python3.9/lib2to3/pgen2

Name	Size	Mode	Actions
__pycache__/	-	0755	rm
conv.py	9642	0644	edit dl rm
driver.py	5969	0644	edit dl rm
grammar.py	5533	0644	edit dl rm
literals.py	1635	0644	edit dl rm
parse.py	8155	0644	edit dl rm
pgen.py	13812	0644	edit dl rm
token.py	1300	0755	edit dl rm
tokenize.py	21119	0644	edit dl rm
__init__.py	143	0644	edit dl rm

Edit: /usr/lib64/python3.9/lib2to3/pgen2/literals.py (1635B)

# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.

"""Safely evaluate Python string literals without using eval()."""

import re

simple_escapes = {"a": "\a",
                  "b": "\b",
                  "f": "\f",
                  "n": "\n",
                  "r": "\r",
                  "t": "\t",
                  "v": "\v",
                  "'": "'",
                  '"': '"',
                  "\\": "\\"}

def escape(m):
    all, tail = m.group(0, 1)
    assert all.startswith("\\")
    esc = simple_escapes.get(tail)
    if esc is not None:
        return esc
    if tail.startswith("x"):
        hexes = tail[1:]
        if len(hexes) < 2:
            raise ValueError("invalid hex string escape ('\\%s')" % tail)
        try:
            i = int(hexes, 16)
        except ValueError:
            raise ValueError("invalid hex string escape ('\\%s')" % tail) from None
    else:
        try:
            i = int(tail, 8)
        except ValueError:
            raise ValueError("invalid octal string escape ('\\%s')" % tail) from None
    return chr(i)

def evalString(s):
    assert s.startswith("'") or s.startswith('"'), repr(s[:1])
    q = s[0]
    if s[:3] == q*3:
        q = q*3
    assert s.endswith(q), repr(s[-len(q):])
    assert len(s) >= 2*len(q)
    s = s[len(q):-len(q)]
    return re.sub(r"\\(\'|\"|\\|[abfnrtv]|x.{0,2}|[0-7]{1,3})", escape, s)

def test():
    for i in range(256):
        c = chr(i)
        s = repr(c)
        e = evalString(s)
        if e != c:
            print(i, c, s, e)

if __name__ == "__main__":
    test()

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