Python3 compat layer cleanup

IPython/core/interactiveshell.py

@@ -2623,10 +2623,10 b' class InteractiveShell(SingletonConfigurable):'
         stb = self.InteractiveTB.get_exception_only(etype, evalue)
         
         exc_info = {
-            u'status' : 'error',
-            u'traceback' : stb,
-            u'ename' : etype.__name__,
-            u'evalue' : py3compat.safe_unicode(evalue),
+            "status": "error",
+            "traceback": stb,
+            "ename": etype.__name__,
+            "evalue": py3compat.safe_unicode(evalue),
         }
 
         return exc_info

IPython/core/magics/script.py

@@ -16,7 +16,6 b' from IPython.core.magic import ('
     Magics, magics_class, line_magic, cell_magic
 )
 from IPython.lib.backgroundjobs import BackgroundJobManager
-from IPython.utils import py3compat
 from IPython.utils.process import arg_split
 from traitlets import List, Dict, default
 

IPython/core/tests/test_inputtransformer.py

@@ -2,7 +2,6 b' import tokenize'
 import nose.tools as nt
 
 from IPython.testing import tools as tt
-from IPython.utils import py3compat
 
 from IPython.core import inputtransformer as ipt
 

IPython/utils/py3compat.py

@@ -55,72 +55,6 b' def safe_unicode(e):'
 
     return u'Unrecoverably corrupt evalue'
 
-# shutil.which from Python 3.4
-def _shutil_which(cmd, mode=os.F_OK | os.X_OK, path=None):
-    """Given a command, mode, and a PATH string, return the path which
-    conforms to the given mode on the PATH, or None if there is no such
-    file.
-
-    `mode` defaults to os.F_OK | os.X_OK. `path` defaults to the result
-    of os.environ.get("PATH"), or can be overridden with a custom search
-    path.
-
-    This is a backport of shutil.which from Python 3.4
-    """
-    # Check that a given file can be accessed with the correct mode.
-    # Additionally check that `file` is not a directory, as on Windows
-    # directories pass the os.access check.
-    def _access_check(fn, mode):
-        return (os.path.exists(fn) and os.access(fn, mode)
-                and not os.path.isdir(fn))
-
-    # If we're given a path with a directory part, look it up directly rather
-    # than referring to PATH directories. This includes checking relative to the
-    # current directory, e.g. ./script
-    if os.path.dirname(cmd):
-        if _access_check(cmd, mode):
-            return cmd
-        return None
-
-    if path is None:
-        path = os.environ.get("PATH", os.defpath)
-    if not path:
-        return None
-    path = path.split(os.pathsep)
-
-    if sys.platform == "win32":
-        # The current directory takes precedence on Windows.
-        if not os.curdir in path:
-            path.insert(0, os.curdir)
-
-        # PATHEXT is necessary to check on Windows.
-        pathext = os.environ.get("PATHEXT", "").split(os.pathsep)
-        # See if the given file matches any of the expected path extensions.
-        # This will allow us to short circuit when given "python.exe".
-        # If it does match, only test that one, otherwise we have to try
-        # others.
-        if any(cmd.lower().endswith(ext.lower()) for ext in pathext):
-            files = [cmd]
-        else:
-            files = [cmd + ext for ext in pathext]
-    else:
-        # On other platforms you don't have things like PATHEXT to tell you
-        # what file suffixes are executable, so just pass on cmd as-is.
-        files = [cmd]
-
-    seen = set()
-    for dir in path:
-        normdir = os.path.normcase(dir)
-        if not normdir in seen:
-            seen.add(normdir)
-            for thefile in files:
-                name = os.path.join(dir, thefile)
-                if _access_check(name, mode):
-                    return name
-    return None
-
-PY3 = True
-
 # keep reference to builtin_mod because the kernel overrides that value
 # to forward requests to a frontend.
 def input(prompt=''):
@@ -129,16 +63,6 b" def input(prompt=''):"
 builtin_mod_name = "builtins"
 import builtins as builtin_mod
 
-
-which = shutil.which
-
-def isidentifier(s, dotted=False):
-    if dotted:
-        return all(isidentifier(a) for a in s.split("."))
-    return s.isidentifier()
-
-getcwd = os.getcwd
-
 MethodType = types.MethodType
 
 def execfile(fname, glob, loc=None, compiler=None):
@@ -147,7 +71,6 b' def execfile(fname, glob, loc=None, compiler=None):'
         compiler = compiler or compile
         exec(compiler(f.read(), fname, 'exec'), glob, loc)
 
-PY2 = not PY3
 PYPY = platform.python_implementation() == "PyPy"
 
 # Cython still rely on that as a Dec 28 2019

IPython/utils/text.py

@@ -15,7 +15,6 b' import textwrap'
 from string import Formatter
 from pathlib import Path
 
-from IPython.utils import py3compat
 
 # datetime.strftime date format for ipython
 if sys.platform == 'win32':