use py3compat.which in common locations

IPython/testing/decorators.py

@@ -1,400 +1,369 b''
 # -*- coding: utf-8 -*-
 """Decorators for labeling test objects.
 
 Decorators that merely return a modified version of the original function
 object are straightforward.  Decorators that return a new function object need
 to use nose.tools.make_decorator(original_function)(decorator) in returning the
 decorator, in order to preserve metadata such as function name, setup and
 teardown functions and so on - see nose.tools for more information.
 
 This module provides a set of useful decorators meant to be ready to use in
 your own tests.  See the bottom of the file for the ready-made ones, and if you
 find yourself writing a new one that may be of generic use, add it here.
 
 Included decorators:
 
 
 Lightweight testing that remains unittest-compatible.
 
 - An @as_unittest decorator can be used to tag any normal parameter-less
   function as a unittest TestCase.  Then, both nose and normal unittest will
   recognize it as such.  This will make it easier to migrate away from Nose if
   we ever need/want to while maintaining very lightweight tests.
 
 NOTE: This file contains IPython-specific decorators. Using the machinery in
 IPython.external.decorators, we import either numpy.testing.decorators if numpy is
 available, OR use equivalent code in IPython.external._decorators, which
 we've copied verbatim from numpy.
 
-Authors
--------
-
-- Fernando Perez <[e-mail]>
 """
 
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2009-2011  The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING, distributed as part of this software.
-#-----------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
-
-# Stdlib imports
 import sys
 import os
 import tempfile
 import unittest
 
-# Third-party imports
-
-# This is Michele Simionato's decorator module, kept verbatim.
 from decorator import decorator
 
 # Expose the unittest-driven decorators
 from .ipunittest import ipdoctest, ipdocstring
 
 # Grab the numpy-specific decorators which we keep in a file that we
 # occasionally update from upstream: decorators.py is a copy of
 # numpy.testing.decorators, we expose all of it here.
 from IPython.external.decorators import *
 
 # For onlyif_cmd_exists decorator
-from IPython.utils.process import is_cmd_found
-from IPython.utils.py3compat import string_types
+from IPython.utils.py3compat import string_types, which
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 # Simple example of the basic idea
 def as_unittest(func):
     """Decorator to make a simple function into a normal test via unittest."""
     class Tester(unittest.TestCase):
         def test(self):
             func()
 
     Tester.__name__ = func.__name__
 
     return Tester
 
 # Utility functions
 
 def apply_wrapper(wrapper,func):
     """Apply a wrapper to a function for decoration.
 
     This mixes Michele Simionato's decorator tool with nose's make_decorator,
     to apply a wrapper in a decorator so that all nose attributes, as well as
     function signature and other properties, survive the decoration cleanly.
     This will ensure that wrapped functions can still be well introspected via
     IPython, for example.
     """
     import nose.tools
 
     return decorator(wrapper,nose.tools.make_decorator(func)(wrapper))
 
 
 def make_label_dec(label,ds=None):
     """Factory function to create a decorator that applies one or more labels.
 
     Parameters
     ----------
       label : string or sequence
       One or more labels that will be applied by the decorator to the functions
     it decorates.  Labels are attributes of the decorated function with their
     value set to True.
 
       ds : string
       An optional docstring for the resulting decorator.  If not given, a
       default docstring is auto-generated.
 
     Returns
     -------
       A decorator.
 
     Examples
     --------
 
     A simple labeling decorator:
 
     >>> slow = make_label_dec('slow')
     >>> slow.__doc__
     "Labels a test as 'slow'."
     
     And one that uses multiple labels and a custom docstring:
     
     >>> rare = make_label_dec(['slow','hard'],
     ... "Mix labels 'slow' and 'hard' for rare tests.")
     >>> rare.__doc__
     "Mix labels 'slow' and 'hard' for rare tests."
 
     Now, let's test using this one:
     >>> @rare
     ... def f(): pass
     ...
     >>>
     >>> f.slow
     True
     >>> f.hard
     True
     """
 
     if isinstance(label, string_types):
         labels = [label]
     else:
         labels = label
 
     # Validate that the given label(s) are OK for use in setattr() by doing a
     # dry run on a dummy function.
     tmp = lambda : None
     for label in labels:
         setattr(tmp,label,True)
 
     # This is the actual decorator we'll return
     def decor(f):
         for label in labels:
             setattr(f,label,True)
         return f
 
     # Apply the user's docstring, or autogenerate a basic one
     if ds is None:
         ds = "Labels a test as %r." % label
     decor.__doc__ = ds
 
     return decor
 
 
 # Inspired by numpy's skipif, but uses the full apply_wrapper utility to
 # preserve function metadata better and allows the skip condition to be a
 # callable.
 def skipif(skip_condition, msg=None):
     ''' Make function raise SkipTest exception if skip_condition is true
 
     Parameters
     ----------
 
     skip_condition : bool or callable
       Flag to determine whether to skip test. If the condition is a
       callable, it is used at runtime to dynamically make the decision. This
       is useful for tests that may require costly imports, to delay the cost
       until the test suite is actually executed.
     msg : string
       Message to give on raising a SkipTest exception.
 
     Returns
     -------
     decorator : function
       Decorator, which, when applied to a function, causes SkipTest
       to be raised when the skip_condition was True, and the function
       to be called normally otherwise.
 
     Notes
     -----
     You will see from the code that we had to further decorate the
     decorator with the nose.tools.make_decorator function in order to
     transmit function name, and various other metadata.
     '''
 
     def skip_decorator(f):
         # Local import to avoid a hard nose dependency and only incur the
         # import time overhead at actual test-time.
         import nose
 
         # Allow for both boolean or callable skip conditions.
         if callable(skip_condition):
             skip_val = skip_condition
         else:
             skip_val = lambda : skip_condition
 
         def get_msg(func,msg=None):
             """Skip message with information about function being skipped."""
             if msg is None: out = 'Test skipped due to test condition.'
             else: out = msg
             return "Skipping test: %s. %s" % (func.__name__,out)
 
         # We need to define *two* skippers because Python doesn't allow both
         # return with value and yield inside the same function.
         def skipper_func(*args, **kwargs):
             """Skipper for normal test functions."""
             if skip_val():
                 raise nose.SkipTest(get_msg(f,msg))
             else:
                 return f(*args, **kwargs)
 
         def skipper_gen(*args, **kwargs):
             """Skipper for test generators."""
             if skip_val():
                 raise nose.SkipTest(get_msg(f,msg))
             else:
                 for x in f(*args, **kwargs):
                     yield x
 
         # Choose the right skipper to use when building the actual generator.
         if nose.util.isgenerator(f):
             skipper = skipper_gen
         else:
             skipper = skipper_func
 
         return nose.tools.make_decorator(f)(skipper)
 
     return skip_decorator
 
 # A version with the condition set to true, common case just to attach a message
 # to a skip decorator
 def skip(msg=None):
     """Decorator factory - mark a test function for skipping from test suite.
 
     Parameters
     ----------
       msg : string
         Optional message to be added.
 
     Returns
     -------
        decorator : function
          Decorator, which, when applied to a function, causes SkipTest
          to be raised, with the optional message added.
       """
 
     return skipif(True,msg)
 
 
 def onlyif(condition, msg):
     """The reverse from skipif, see skipif for details."""
 
     if callable(condition):
         skip_condition = lambda : not condition()
     else:
         skip_condition = lambda : not condition
 
     return skipif(skip_condition, msg)
 
 #-----------------------------------------------------------------------------
 # Utility functions for decorators
 def module_not_available(module):
     """Can module be imported?  Returns true if module does NOT import.
 
     This is used to make a decorator to skip tests that require module to be
     available, but delay the 'import numpy' to test execution time.
     """
     try:
         mod = __import__(module)
         mod_not_avail = False
     except ImportError:
         mod_not_avail = True
 
     return mod_not_avail
 
 
 def decorated_dummy(dec, name):
     """Return a dummy function decorated with dec, with the given name.
     
     Examples
     --------
     import IPython.testing.decorators as dec
     setup = dec.decorated_dummy(dec.skip_if_no_x11, __name__)
     """
     dummy = lambda: None
     dummy.__name__ = name
     return dec(dummy)
 
 #-----------------------------------------------------------------------------
 # Decorators for public use
 
 # Decorators to skip certain tests on specific platforms.
 skip_win32 = skipif(sys.platform == 'win32',
                     "This test does not run under Windows")
 skip_linux = skipif(sys.platform.startswith('linux'),
                     "This test does not run under Linux")
 skip_osx = skipif(sys.platform == 'darwin',"This test does not run under OS X")
 
 
 # Decorators to skip tests if not on specific platforms.
 skip_if_not_win32 = skipif(sys.platform != 'win32',
                            "This test only runs under Windows")
 skip_if_not_linux = skipif(not sys.platform.startswith('linux'),
                            "This test only runs under Linux")
 skip_if_not_osx = skipif(sys.platform != 'darwin',
                          "This test only runs under OSX")
 
 
 _x11_skip_cond = (sys.platform not in ('darwin', 'win32') and
                   os.environ.get('DISPLAY', '') == '')
 _x11_skip_msg = "Skipped under *nix when X11/XOrg not available"
 
 skip_if_no_x11 = skipif(_x11_skip_cond, _x11_skip_msg)
 
 # not a decorator itself, returns a dummy function to be used as setup
 def skip_file_no_x11(name):
     return decorated_dummy(skip_if_no_x11, name) if _x11_skip_cond else None
 
 # Other skip decorators
 
 # generic skip without module
 skip_without = lambda mod: skipif(module_not_available(mod), "This test requires %s" % mod)
 
 skipif_not_numpy = skip_without('numpy')
 
 skipif_not_matplotlib = skip_without('matplotlib')
 
 skipif_not_sympy = skip_without('sympy')
 
 skip_known_failure = knownfailureif(True,'This test is known to fail')
 
 known_failure_py3 = knownfailureif(sys.version_info[0] >= 3, 
                                     'This test is known to fail on Python 3.')
 
 # A null 'decorator', useful to make more readable code that needs to pick
 # between different decorators based on OS or other conditions
 null_deco = lambda f: f
 
 # Some tests only run where we can use unicode paths. Note that we can't just
 # check os.path.supports_unicode_filenames, which is always False on Linux.
 try:
     f = tempfile.NamedTemporaryFile(prefix=u"tmp€")
 except UnicodeEncodeError:
     unicode_paths = False
 else:
     unicode_paths = True
     f.close()
 
 onlyif_unicode_paths = onlyif(unicode_paths, ("This test is only applicable "
                                     "where we can use unicode in filenames."))
 
 
 def onlyif_cmds_exist(*commands):
     """
     Decorator to skip test when at least one of `commands` is not found.
     """
     for cmd in commands:
-        try:
-            if not is_cmd_found(cmd):
-                return skip("This test runs only if command '{0}' "
-                            "is installed".format(cmd))
-        except ImportError as e:
-            # is_cmd_found uses pywin32 on windows, which might not be available
-            if sys.platform == 'win32' and 'pywin32' in str(e):
-                return skip("This test runs only if pywin32 and command '{0}' "
-                            "is installed".format(cmd))
-            raise e
+        if not which(cmd):
+            return skip("This test runs only if command '{0}' "
+                        "is installed".format(cmd))
     return null_deco
 
 def onlyif_any_cmd_exists(*commands):
     """
     Decorator to skip test unless at least one of `commands` is found.
     """
     for cmd in commands:
-        try:
-            if is_cmd_found(cmd):
-                return null_deco
-        except ImportError as e:
-            # is_cmd_found uses pywin32 on windows, which might not be available
-            if sys.platform == 'win32' and 'pywin32' in str(e):
-                return skip("This test runs only if pywin32 and commands '{0}' "
-                            "are installed".format(commands))
-            raise e
+        if which(cmd):
+            return null_deco
     return skip("This test runs only if one of the commands {0} "
                 "is installed".format(commands))

IPython/utils/process.py

@@ -1,123 +1,106 b''
 # encoding: utf-8
 """
 Utilities for working with external processes.
 """
 
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2008-2011  The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING, distributed as part of this software.
-#-----------------------------------------------------------------------------
-
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
+
 from __future__ import print_function
 
-# Stdlib
 import os
 import sys
 
-# Our own
 if sys.platform == 'win32':
-    from ._process_win32 import _find_cmd, system, getoutput, arg_split, check_pid
+    from ._process_win32 import system, getoutput, arg_split, check_pid
 elif sys.platform == 'cli':
-    from ._process_cli import _find_cmd, system, getoutput, arg_split, check_pid
+    from ._process_cli import system, getoutput, arg_split, check_pid
 else:
-    from ._process_posix import _find_cmd, system, getoutput, arg_split, check_pid
+    from ._process_posix import system, getoutput, arg_split, check_pid
 
 from ._process_common import getoutputerror, get_output_error_code, process_handler
 from . import py3compat
 
-#-----------------------------------------------------------------------------
-# Code
-#-----------------------------------------------------------------------------
-
 
 class FindCmdError(Exception):
     pass
 
 
 def find_cmd(cmd):
     """Find absolute path to executable cmd in a cross platform manner.
 
     This function tries to determine the full path to a command line program
     using `which` on Unix/Linux/OS X and `win32api` on Windows.  Most of the
     time it will use the version that is first on the users `PATH`.
 
     Warning, don't use this to find IPython command line programs as there
     is a risk you will find the wrong one.  Instead find those using the
     following code and looking for the application itself::
 
         from IPython.utils.path import get_ipython_module_path
         from IPython.utils.process import pycmd2argv
         argv = pycmd2argv(get_ipython_module_path('IPython.terminal.ipapp'))
 
     Parameters
     ----------
     cmd : str
         The command line program to look for.
     """
-    try:
-        path = _find_cmd(cmd).rstrip()
-    except OSError:
-        raise FindCmdError('command could not be found: %s' % cmd)
-    # which returns empty if not found
-    if path == '':
+    path = py3compat.which(cmd)
+    if path is None:
         raise FindCmdError('command could not be found: %s' % cmd)
-    return os.path.abspath(path)
+    return path
 
 
 def is_cmd_found(cmd):
     """Check whether executable `cmd` exists or not and return a bool."""
     try:
         find_cmd(cmd)
         return True
     except FindCmdError:
         return False
 
 
 def pycmd2argv(cmd):
     r"""Take the path of a python command and return a list (argv-style).
 
     This only works on Python based command line programs and will find the
     location of the ``python`` executable using ``sys.executable`` to make
     sure the right version is used.
 
     For a given path ``cmd``, this returns [cmd] if cmd's extension is .exe,
     .com or .bat, and [, cmd] otherwise.
 
     Parameters
     ----------
     cmd : string
       The path of the command.
 
     Returns
     -------
     argv-style list.
     """
     ext = os.path.splitext(cmd)[1]
     if ext in ['.exe', '.com', '.bat']:
         return [cmd]
     else:
         return [sys.executable, cmd]
 
 
 def abbrev_cwd():
     """ Return abbreviated version of cwd, e.g. d:mydir """
     cwd = py3compat.getcwd().replace('\\','/')
     drivepart = ''
     tail = cwd
     if sys.platform == 'win32':
         if len(cwd) < 4:
             return cwd
         drivepart,tail = os.path.splitdrive(cwd)
 
 
     parts = tail.split('/')
     if len(parts) > 2:
         tail = '/'.join(parts[-2:])
 
     return (drivepart + (
         cwd == '/' and '/' or tail))

jupyter_nbconvert/exporters/pdf.py

@@ -1,147 +1,149 b''
 """Export to PDF via latex"""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import subprocess
 import os
 import sys
 
-from IPython.utils.process import find_cmd
+from IPython.utils.py3compat import which
 from IPython.utils.traitlets import Integer, List, Bool, Instance
 from IPython.utils.tempdir import TemporaryWorkingDirectory
 from .latex import LatexExporter
 
 
 class PDFExporter(LatexExporter):
     """Writer designed to write to PDF files"""
 
     latex_count = Integer(3, config=True,
         help="How many times latex will be called."
     )
 
     latex_command = List([u"pdflatex", u"{filename}"], config=True, 
         help="Shell command used to compile latex."
     )
 
     bib_command = List([u"bibtex", u"{filename}"], config=True,
         help="Shell command used to run bibtex."
     )
 
     verbose = Bool(False, config=True,
         help="Whether to display the output of latex commands."
     )
 
     temp_file_exts = List(['.aux', '.bbl', '.blg', '.idx', '.log', '.out'], config=True,
         help="File extensions of temp files to remove after running."
     )
     
     writer = Instance("jupyter_nbconvert.writers.FilesWriter", args=())
 
     def run_command(self, command_list, filename, count, log_function):
         """Run command_list count times.
         
         Parameters
         ----------
         command_list : list
             A list of args to provide to Popen. Each element of this
             list will be interpolated with the filename to convert.
         filename : unicode
             The name of the file to convert.
         count : int
             How many times to run the command.
         
         Returns
         -------
         success : bool
             A boolean indicating if the command was successful (True)
             or failed (False).
         """
         command = [c.format(filename=filename) for c in command_list]
 
         # On windows with python 2.x there is a bug in subprocess.Popen and
         # unicode commands are not supported
         if sys.platform == 'win32' and sys.version_info < (3,0):
             #We must use cp1252 encoding for calling subprocess.Popen
             #Note that sys.stdin.encoding and encoding.DEFAULT_ENCODING
             # could be different (cp437 in case of dos console)
-            command = [c.encode('cp1252') for c in command]        
+            command = [c.encode('cp1252') for c in command]
 
         # This will throw a clearer error if the command is not found
-        find_cmd(command_list[0])
+        cmd = which(command_list[0])
+        if cmd is None:
+            raise OSError("%s not found on PATH" % command_list[0])
         
         times = 'time' if count == 1 else 'times'
         self.log.info("Running %s %i %s: %s", command_list[0], count, times, command)
         with open(os.devnull, 'rb') as null:
             stdout = subprocess.PIPE if not self.verbose else None
             for index in range(count):
                 p = subprocess.Popen(command, stdout=stdout, stdin=null)
                 out, err = p.communicate()
                 if p.returncode:
                     if self.verbose:
                         # verbose means I didn't capture stdout with PIPE,
                         # so it's already been displayed and `out` is None.
                         out = u''
                     else:
                         out = out.decode('utf-8', 'replace')
                     log_function(command, out)
                     return False # failure
         return True # success
 
     def run_latex(self, filename):
         """Run pdflatex self.latex_count times."""
 
         def log_error(command, out):
             self.log.critical(u"%s failed: %s\n%s", command[0], command, out)
 
         return self.run_command(self.latex_command, filename, 
             self.latex_count, log_error)
 
     def run_bib(self, filename):
         """Run bibtex self.latex_count times."""
         filename = os.path.splitext(filename)[0]
 
         def log_error(command, out):
             self.log.warn('%s had problems, most likely because there were no citations',
                 command[0])
             self.log.debug(u"%s output: %s\n%s", command[0], command, out)
 
         return self.run_command(self.bib_command, filename, 1, log_error)
 
     def clean_temp_files(self, filename):
         """Remove temporary files created by pdflatex/bibtex."""
         self.log.info("Removing temporary LaTeX files")
         filename = os.path.splitext(filename)[0]
         for ext in self.temp_file_exts:
             try:
                 os.remove(filename+ext)
             except OSError:
                 pass
 
     def from_notebook_node(self, nb, resources=None, **kw):
         latex, resources = super(PDFExporter, self).from_notebook_node(
             nb, resources=resources, **kw
         )
         with TemporaryWorkingDirectory() as td:
             notebook_name = "notebook"
             tex_file = self.writer.write(latex, resources, notebook_name=notebook_name)
             self.log.info("Building PDF")
             rc = self.run_latex(tex_file)
             if not rc:
                 rc = self.run_bib(tex_file)
             if not rc:
                 rc = self.run_latex(tex_file)
             
             pdf_file = notebook_name + '.pdf'
             if not os.path.isfile(pdf_file):
                 raise RuntimeError("PDF creating failed")
             self.log.info('PDF successfully created')
             with open(pdf_file, 'rb') as f:
                 pdf_data = f.read()
         
         # convert output extension to pdf
         # the writer above required it to be tex
         resources['output_extension'] = '.pdf'
         
         return pdf_data, resources