Use pathlib in packaging.py, io.py, and gen_latex_symbols.py

* Added pathlib in a few places where it makes sense to.

IPython/core/magics/packaging.py

@@ -1,104 +1,105 b''
 """Implementation of packaging-related magic functions.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2018 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 import re
 import shlex
 import sys
+from Pathlib import Path
 
 from pathlib import Path
 from IPython.core.magic import Magics, magics_class, line_magic
 
 
 def _is_conda_environment():
     """Return True if the current Python executable is in a conda env"""
     # TODO: does this need to change on windows?
     return Path(sys.prefix, "conda-meta", "history").exists()
 
 
 def _get_conda_executable():
     """Find the path to the conda executable"""
     # Check if there is a conda executable in the same directory as the Python executable.
     # This is the case within conda's root environment.
     conda = Path(sys.executable).parent / "conda"
     if conda.isfile():
         return str(conda)
 
     # Otherwise, attempt to extract the executable from conda history.
     # This applies in any conda environment.
     history = Path(sys.prefix, "conda-meta", "history").read_text()
     match = re.search(
         r"^#\s*cmd:\s*(?P<command>.*conda)\s[create|install]",
         history,
         flags=re.MULTILINE,
     )
     if match:
         return match.groupdict()["command"]
     
     # Fallback: assume conda is available on the system path.
     return "conda"
 
 
 CONDA_COMMANDS_REQUIRING_PREFIX = {
     'install', 'list', 'remove', 'uninstall', 'update', 'upgrade',
 }
 CONDA_COMMANDS_REQUIRING_YES = {
     'install', 'remove', 'uninstall', 'update', 'upgrade',
 }
 CONDA_ENV_FLAGS = {'-p', '--prefix', '-n', '--name'}
 CONDA_YES_FLAGS = {'-y', '--y'}
 
 
 @magics_class
 class PackagingMagics(Magics):
     """Magics related to packaging & installation"""
 
     @line_magic
     def pip(self, line):
         """Run the pip package manager within the current kernel.
 
         Usage:
           %pip install [pkgs]
         """
         self.shell.system(' '.join([sys.executable, '-m', 'pip', line]))
         print("Note: you may need to restart the kernel to use updated packages.")
 
     @line_magic
     def conda(self, line):
         """Run the conda package manager within the current kernel.
         
         Usage:
           %conda install [pkgs]
         """
         if not _is_conda_environment():
             raise ValueError("The python kernel does not appear to be a conda environment.  "
                              "Please use ``%pip install`` instead.")
         
         conda = _get_conda_executable()
         args = shlex.split(line)
         command = args[0]
         args = args[1:]
         extra_args = []
 
         # When the subprocess does not allow us to respond "yes" during the installation,
         # we need to insert --yes in the argument list for some commands
         stdin_disabled = getattr(self.shell, 'kernel', None) is not None
         needs_yes = command in CONDA_COMMANDS_REQUIRING_YES
         has_yes = set(args).intersection(CONDA_YES_FLAGS)
         if stdin_disabled and needs_yes and not has_yes:
             extra_args.append("--yes")
 
         # Add --prefix to point conda installation to the current environment
         needs_prefix = command in CONDA_COMMANDS_REQUIRING_PREFIX
         has_prefix = set(args).intersection(CONDA_ENV_FLAGS)
         if needs_prefix and not has_prefix:
             extra_args.extend(["--prefix", sys.prefix])
 
         self.shell.system(' '.join([conda, command] + extra_args + args))
         print("\nNote: you may need to restart the kernel to use updated packages.")

IPython/utils/io.py

@@ -1,248 +1,249 b''
 # encoding: utf-8
 """
 IO related utilities.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 
 import atexit
 import os
 import sys
 import tempfile
 import warnings
 from warnings import warn
+from pathlib import Path
 
 from IPython.utils.decorators import undoc
 from .capture import CapturedIO, capture_output
 
 @undoc
 class IOStream:
 
     def __init__(self, stream, fallback=None):
         warn('IOStream is deprecated since IPython 5.0, use sys.{stdin,stdout,stderr} instead',
              DeprecationWarning, stacklevel=2)
         if not hasattr(stream,'write') or not hasattr(stream,'flush'):
             if fallback is not None:
                 stream = fallback
             else:
                 raise ValueError("fallback required, but not specified")
         self.stream = stream
         self._swrite = stream.write
 
         # clone all methods not overridden:
         def clone(meth):
             return not hasattr(self, meth) and not meth.startswith('_')
         for meth in filter(clone, dir(stream)):
             try:
                 val = getattr(stream, meth)
             except AttributeError:
                 pass
             else:
                 setattr(self, meth, val)
 
     def __repr__(self):
         cls = self.__class__
         tpl = '{mod}.{cls}({args})'
         return tpl.format(mod=cls.__module__, cls=cls.__name__, args=self.stream)
 
     def write(self,data):
         warn('IOStream is deprecated since IPython 5.0, use sys.{stdin,stdout,stderr} instead',
              DeprecationWarning, stacklevel=2)
         try:
             self._swrite(data)
         except:
             try:
                 # print handles some unicode issues which may trip a plain
                 # write() call.  Emulate write() by using an empty end
                 # argument.
                 print(data, end='', file=self.stream)
             except:
                 # if we get here, something is seriously broken.
                 print('ERROR - failed to write data to stream:', self.stream,
                       file=sys.stderr)
 
     def writelines(self, lines):
         warn('IOStream is deprecated since IPython 5.0, use sys.{stdin,stdout,stderr} instead',
              DeprecationWarning, stacklevel=2)
         if isinstance(lines, str):
             lines = [lines]
         for line in lines:
             self.write(line)
 
     # This class used to have a writeln method, but regular files and streams
     # in Python don't have this method. We need to keep this completely
     # compatible so we removed it.
 
     @property
     def closed(self):
         return self.stream.closed
 
     def close(self):
         pass
 
 # setup stdin/stdout/stderr to sys.stdin/sys.stdout/sys.stderr
 devnull = open(os.devnull, 'w')
 atexit.register(devnull.close)
 
 # io.std* are deprecated, but don't show our own deprecation warnings
 # during initialization of the deprecated API.
 with warnings.catch_warnings():
     warnings.simplefilter('ignore', DeprecationWarning)
     stdin = IOStream(sys.stdin, fallback=devnull)
     stdout = IOStream(sys.stdout, fallback=devnull)
     stderr = IOStream(sys.stderr, fallback=devnull)
 
 class Tee(object):
     """A class to duplicate an output stream to stdout/err.
 
     This works in a manner very similar to the Unix 'tee' command.
 
     When the object is closed or deleted, it closes the original file given to
     it for duplication.
     """
     # Inspired by:
     # http://mail.python.org/pipermail/python-list/2007-May/442737.html
 
     def __init__(self, file_or_name, mode="w", channel='stdout'):
         """Construct a new Tee object.
 
         Parameters
         ----------
         file_or_name : filename or open filehandle (writable)
           File that will be duplicated
 
         mode : optional, valid mode for open().
           If a filename was give, open with this mode.
 
         channel : str, one of ['stdout', 'stderr']
         """
         if channel not in ['stdout', 'stderr']:
             raise ValueError('Invalid channel spec %s' % channel)
 
         if hasattr(file_or_name, 'write') and hasattr(file_or_name, 'seek'):
             self.file = file_or_name
         else:
             self.file = open(file_or_name, mode)
         self.channel = channel
         self.ostream = getattr(sys, channel)
         setattr(sys, channel, self)
         self._closed = False
 
     def close(self):
         """Close the file and restore the channel."""
         self.flush()
         setattr(sys, self.channel, self.ostream)
         self.file.close()
         self._closed = True
 
     def write(self, data):
         """Write data to both channels."""
         self.file.write(data)
         self.ostream.write(data)
         self.ostream.flush()
 
     def flush(self):
         """Flush both channels."""
         self.file.flush()
         self.ostream.flush()
 
     def __del__(self):
         if not self._closed:
             self.close()
 
 
 def ask_yes_no(prompt, default=None, interrupt=None):
     """Asks a question and returns a boolean (y/n) answer.
 
     If default is given (one of 'y','n'), it is used if the user input is
     empty. If interrupt is given (one of 'y','n'), it is used if the user
     presses Ctrl-C. Otherwise the question is repeated until an answer is
     given.
 
     An EOF is treated as the default answer.  If there is no default, an
     exception is raised to prevent infinite loops.
 
     Valid answers are: y/yes/n/no (match is not case sensitive)."""
 
     answers = {'y':True,'n':False,'yes':True,'no':False}
     ans = None
     while ans not in answers.keys():
         try:
             ans = input(prompt+' ').lower()
             if not ans:  # response was an empty string
                 ans = default
         except KeyboardInterrupt:
             if interrupt:
                 ans = interrupt
             print("\r")
         except EOFError:
             if default in answers.keys():
                 ans = default
                 print()
             else:
                 raise
 
     return answers[ans]
 
 
 def temp_pyfile(src, ext='.py'):
     """Make a temporary python file, return filename and filehandle.
 
     Parameters
     ----------
     src : string or list of strings (no need for ending newlines if list)
       Source code to be written to the file.
 
     ext : optional, string
       Extension for the generated file.
 
     Returns
     -------
     (filename, open filehandle)
       It is the caller's responsibility to close the open file and unlink it.
     """
-    fname = tempfile.mkstemp(ext)[1]
-    with open(fname,'w') as f:
+    fname = Path(tempfile.mkstemp(ext)[1])
+    with fname.open('w') as f:
         f.write(src)
         f.flush()
     return fname
 
 @undoc
 def atomic_writing(*args, **kwargs):
     """DEPRECATED: moved to notebook.services.contents.fileio"""
     warn("IPython.utils.io.atomic_writing has moved to notebook.services.contents.fileio since IPython 4.0", DeprecationWarning, stacklevel=2)
     from notebook.services.contents.fileio import atomic_writing
     return atomic_writing(*args, **kwargs)
 
 @undoc
 def raw_print(*args, **kw):
     """DEPRECATED: Raw print to sys.__stdout__, otherwise identical interface to print()."""
     warn("IPython.utils.io.raw_print has been deprecated since IPython 7.0", DeprecationWarning, stacklevel=2)
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stdout__)
     sys.__stdout__.flush()
 
 @undoc
 def raw_print_err(*args, **kw):
     """DEPRECATED: Raw print to sys.__stderr__, otherwise identical interface to print()."""
     warn("IPython.utils.io.raw_print_err has been deprecated since IPython 7.0", DeprecationWarning, stacklevel=2)
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stderr__)
     sys.__stderr__.flush()
 
 # used by IPykernel <- 4.9. Removed during IPython 7-dev period and re-added 
 # Keep for a version or two then should remove
 rprint = raw_print
 rprinte = raw_print_err
 
 @undoc
 def unicode_std_stream(stream='stdout'):
     """DEPRECATED, moved to nbconvert.utils.io"""
     warn("IPython.utils.io.unicode_std_stream has moved to nbconvert.utils.io since IPython 4.0", DeprecationWarning, stacklevel=2)
     from nbconvert.utils.io import unicode_std_stream
     return unicode_std_stream(stream)

tools/gen_latex_symbols.py

@@ -1,88 +1,87 b''
 # coding: utf-8
 
 # This script autogenerates `IPython.core.latex_symbols.py`, which contains a
 # single dict , named `latex_symbols`. The keys in this dict are latex symbols,
 # such as `\\alpha` and the values in the dict are the unicode equivalents for
 # those. Most importantly, only unicode symbols that are valid identifiers in
 # Python 3 are included. 
 
 # 
 # The original mapping of latex symbols to unicode comes from the `latex_symbols.jl` files from Julia.
 
-import os, sys
+from pathlib import Path
 
 # Import the Julia LaTeX symbols
 print('Importing latex_symbols.js from Julia...')
 import requests
 url = 'https://raw.githubusercontent.com/JuliaLang/julia/master/stdlib/REPL/src/latex_symbols.jl'
 r = requests.get(url)
 
 
 # Build a list of key, value pairs
 print('Building a list of (latex, unicode) key-value pairs...')
 lines = r.text.splitlines()
 
 prefixes_line = lines.index('# "font" prefixes')
 symbols_line = lines.index('# manual additions:')
 
 prefix_dict = {}
 for l in lines[prefixes_line + 1: symbols_line]:
     p = l.split()
     if not p or p[1] == 'latex_symbols': continue
     prefix_dict[p[1]] = p[3]
 
 idents = []
 for l in lines[symbols_line:]:
     if not '=>' in l: continue # if it's not a def, skip
     if '#' in l: l = l[:l.index('#')] # get rid of eol comments
     x, y = l.strip().split('=>') 
     if '*' in x: # if a prefix is present substitute it with its value
         p, x = x.split('*')
         x = prefix_dict[p][:-1] + x[1:]
     x, y = x.split('"')[1], y.split('"')[1] # get the values in quotes
     idents.append((x, y))
 
 # Filter out non-valid identifiers
 print('Filtering out characters that are not valid Python 3 identifiers')
 
 def test_ident(i):
     """Is the unicode string valid in a Python 3 identifier."""
     # Some characters are not valid at the start of a name, but we still want to
     # include them. So prefix with 'a', which is valid at the start.
     return ('a' + i).isidentifier()
 
 assert test_ident("α")
 assert not test_ident('‴')
 
 valid_idents = [line for line in idents if test_ident(line[1])]
 
 # Write the `latex_symbols.py` module in the cwd
 
 s = """# encoding: utf-8
 
 # DO NOT EDIT THIS FILE BY HAND.
 
 # To update this file, run the script /tools/gen_latex_symbols.py using Python 3
 
 # This file is autogenerated from the file:
 # https://raw.githubusercontent.com/JuliaLang/julia/master/base/latex_symbols.jl
 # This original list is filtered to remove any unicode characters that are not valid
 # Python identifiers.
 
 latex_symbols = {\n
 """
 for line in valid_idents:
     s += '    "%s" : "%s",\n' % (line[0], line[1])
 s += "}\n"
 
 s += """
 
 reverse_latex_symbol = { v:k for k,v in latex_symbols.items()}
 """
 
-fn = os.path.join('..','IPython','core','latex_symbols.py')
-print("Writing the file: %s" % fn)
-with open(fn, 'w', encoding='utf-8') as f:
-    f.write(s)
+fn = Path('..', 'IPython', 'core', 'latex_symbols.py')
+print("Writing the file: %s" % str(fn))
+fn.write_text(s, encoding='utf-8')