Vendor shutil.get_terminal_size.

Use the vendored version only if import error.
That should fix import error for many users.

Closes  #9815.

This is only against the 5.x branch as this is in the stdlib on Python 3

IPython/utils/_get_terminal_size.py

@@ -0,0 +1,103 b''
+# vendored version of backports.get_terminal_size as nemesapece package are a
+# mess and break, especially on ubuntu. This file is under MIT Licence. 
+# See https://pypi.python.org/pypi/backports.shutil_get_terminal_size
+"""This is a backport of shutil.get_terminal_size from Python 3.3.
+
+The original implementation is in C, but here we use the ctypes and
+fcntl modules to create a pure Python version of os.get_terminal_size.
+"""
+
+import os
+import struct
+import sys
+
+from collections import namedtuple
+
+__all__ = ["get_terminal_size"]
+
+
+terminal_size = namedtuple("terminal_size", "columns lines")
+
+try:
+    from ctypes import windll, create_string_buffer
+
+    _handles = {
+        0: windll.kernel32.GetStdHandle(-10),
+        1: windll.kernel32.GetStdHandle(-11),
+        2: windll.kernel32.GetStdHandle(-12),
+    }
+
+    def _get_terminal_size(fd):
+        columns = lines = 0
+
+        try:
+            handle = _handles[fd]
+            csbi = create_string_buffer(22)
+            res = windll.kernel32.GetConsoleScreenBufferInfo(handle, csbi)
+            if res:
+                res = struct.unpack("hhhhHhhhhhh", csbi.raw)
+                left, top, right, bottom = res[5:9]
+                columns = right - left + 1
+                lines = bottom - top + 1
+        except Exception:
+            pass
+
+        return terminal_size(columns, lines)
+
+except ImportError:
+    import fcntl
+    import termios
+
+    def _get_terminal_size(fd):
+        try:
+            res = fcntl.ioctl(fd, termios.TIOCGWINSZ, b"\x00" * 4)
+            lines, columns = struct.unpack("hh", res)
+        except Exception:
+            columns = lines = 0
+
+        return terminal_size(columns, lines)
+
+
+def get_terminal_size(fallback=(80, 24)):
+    """Get the size of the terminal window.
+
+    For each of the two dimensions, the environment variable, COLUMNS
+    and LINES respectively, is checked. If the variable is defined and
+    the value is a positive integer, it is used.
+
+    When COLUMNS or LINES is not defined, which is the common case,
+    the terminal connected to sys.__stdout__ is queried
+    by invoking os.get_terminal_size.
+
+    If the terminal size cannot be successfully queried, either because
+    the system doesn't support querying, or because we are not
+    connected to a terminal, the value given in fallback parameter
+    is used. Fallback defaults to (80, 24) which is the default
+    size used by many terminal emulators.
+
+    The value returned is a named tuple of type os.terminal_size.
+    """
+    # Try the environment first
+    try:
+        columns = int(os.environ["COLUMNS"])
+    except (KeyError, ValueError):
+        columns = 0
+
+    try:
+        lines = int(os.environ["LINES"])
+    except (KeyError, ValueError):
+        lines = 0
+
+    # Only query if necessary
+    if columns <= 0 or lines <= 0:
+        try:
+            size = _get_terminal_size(sys.__stdout__.fileno())
+        except (NameError, OSError):
+            size = terminal_size(*fallback)
+
+        if columns <= 0:
+            columns = size.columns
+        if lines <= 0:
+            lines = size.lines
+
+    return terminal_size(columns, lines)

IPython/utils/terminal.py

@@ -1,120 +1,125 b''
 # encoding: utf-8
 """
 Utilities for working with terminals.
 
 Authors:
 
 * Brian E. Granger
 * Fernando Perez
 * Alexander Belchenko (e-mail: bialix AT ukr.net)
 """
 
+from __future__ import absolute_import
+
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import os
 import sys
 import warnings
 try:
     from shutil import get_terminal_size as _get_terminal_size
 except ImportError:
     # use backport on Python 2
+    try:
     from backports.shutil_get_terminal_size import get_terminal_size as _get_terminal_size
+    except ImportError:
+        from ._get_terminal_size import _get_terminal_size
 
 from . import py3compat
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 # This variable is part of the expected API of the module:
 ignore_termtitle = True
 
 
 
 if os.name == 'posix':
     def _term_clear():
         os.system('clear')
 elif sys.platform == 'win32':
     def _term_clear():
         os.system('cls')
 else:
     def _term_clear():
         pass
 
 
 
 def toggle_set_term_title(val):
     """Control whether set_term_title is active or not.
 
     set_term_title() allows writing to the console titlebar.  In embedded
     widgets this can cause problems, so this call can be used to toggle it on
     or off as needed.
 
     The default state of the module is for the function to be disabled.
 
     Parameters
     ----------
       val : bool
         If True, set_term_title() actually writes to the terminal (using the
         appropriate platform-specific module).  If False, it is a no-op.
     """
     global ignore_termtitle
     ignore_termtitle = not(val)
 
 
 def _set_term_title(*args,**kw):
     """Dummy no-op."""
     pass
 
 
 def _set_term_title_xterm(title):
     """ Change virtual terminal title in xterm-workalikes """
     sys.stdout.write('\033]0;%s\007' % title)
 
 if os.name == 'posix':
     TERM = os.environ.get('TERM','')
     if TERM.startswith('xterm'):
         _set_term_title = _set_term_title_xterm
 elif sys.platform == 'win32':
     try:
         import ctypes
 
         SetConsoleTitleW = ctypes.windll.kernel32.SetConsoleTitleW
         SetConsoleTitleW.argtypes = [ctypes.c_wchar_p]
     
         def _set_term_title(title):
             """Set terminal title using ctypes to access the Win32 APIs."""
             SetConsoleTitleW(title)
     except ImportError:
         def _set_term_title(title):
             """Set terminal title using the 'title' command."""
             global ignore_termtitle
 
             try:
                 # Cannot be on network share when issuing system commands
                 curr = py3compat.getcwd()
                 os.chdir("C:")
                 ret = os.system("title " + title)
             finally:
                 os.chdir(curr)
             if ret:
                 # non-zero return code signals error, don't try again
                 ignore_termtitle = True
 
 
 def set_term_title(title):
     """Set terminal title using the necessary platform-dependent calls."""
     if ignore_termtitle:
         return
     _set_term_title(title)
 
 
 def freeze_term_title():
     warnings.warn("This function is deprecated, use toggle_set_term_title()")
     global ignore_termtitle
     ignore_termtitle = True
 
 
 def get_terminal_size(defaultx=80, defaulty=25):
     return _get_terminal_size((defaultx, defaulty))