_utils.py

import os
import subprocess
from platform import system as _curos
import re
CUR_OS = _curos()
IS_WIN = CUR_OS in ['Windows', 'cli']
IS_NIX = (not IS_WIN) and any(
    CUR_OS.startswith(i) for i in
    ['CYGWIN', 'MSYS', 'Linux', 'Darwin', 'SunOS',
     'FreeBSD', 'NetBSD', 'OpenBSD'])
RE_ANSI = re.compile(r"\x1b\[[;\d]*[A-Za-z]")


# Py2/3 compat. Empty conditional to avoid coverage
if True:  # pragma: no cover
    try:
        _range = xrange
    except NameError:
        _range = range

    try:
        _unich = unichr
    except NameError:
        _unich = chr

    try:
        _unicode = unicode
    except NameError:
        _unicode = str

    try:
        if IS_WIN:
            import colorama
            colorama.init()
        else:
            colorama = None
    except ImportError:
        colorama = None

    try:
        from weakref import WeakSet
    except ImportError:
        WeakSet = set

    try:
        _basestring = basestring
    except NameError:
        _basestring = str

    try:  # py>=2.7,>=3.1
        from collections import OrderedDict as _OrderedDict
    except ImportError:
        try:  # older Python versions with backported ordereddict lib
            from ordereddict import OrderedDict as _OrderedDict
        except ImportError:  # older Python versions without ordereddict lib
            # Py2.6,3.0 compat, from PEP 372
            from collections import MutableMapping

            class _OrderedDict(dict, MutableMapping):
                # Methods with direct access to underlying attributes
                def __init__(self, *args, **kwds):
                    if len(args) > 1:
                        raise TypeError('expected at 1 argument, got %d',
                                        len(args))
                    if not hasattr(self, '_keys'):
                        self._keys = []
                    self.update(*args, **kwds)

                def clear(self):
                    del self._keys[:]
                    dict.clear(self)

                def __setitem__(self, key, value):
                    if key not in self:
                        self._keys.append(key)
                    dict.__setitem__(self, key, value)

                def __delitem__(self, key):
                    dict.__delitem__(self, key)
                    self._keys.remove(key)

                def __iter__(self):
                    return iter(self._keys)

                def __reversed__(self):
                    return reversed(self._keys)

                def popitem(self):
                    if not self:
                        raise KeyError
                    key = self._keys.pop()
                    value = dict.pop(self, key)
                    return key, value

                def __reduce__(self):
                    items = [[k, self[k]] for k in self]
                    inst_dict = vars(self).copy()
                    inst_dict.pop('_keys', None)
                    return self.__class__, (items,), inst_dict

                # Methods with indirect access via the above methods
                setdefault = MutableMapping.setdefault
                update = MutableMapping.update
                pop = MutableMapping.pop
                keys = MutableMapping.keys
                values = MutableMapping.values
                items = MutableMapping.items

                def __repr__(self):
                    pairs = ', '.join(map('%r: %r'.__mod__, self.items()))
                    return '%s({%s})' % (self.__class__.__name__, pairs)

                def copy(self):
                    return self.__class__(self)

                @classmethod
                def fromkeys(cls, iterable, value=None):
                    d = cls()
                    for key in iterable:
                        d[key] = value
                    return d


class Comparable(object):
    """Assumes child has self._comparable attr/@property"""
    def __lt__(self, other):
        return self._comparable < other._comparable

    def __le__(self, other):
        return (self < other) or (self == other)

    def __eq__(self, other):
        return self._comparable == other._comparable

    def __ne__(self, other):
        return not self == other

    def __gt__(self, other):
        return not self <= other

    def __ge__(self, other):
        return not self < other


class SimpleTextIOWrapper(object):
    """
    Change only `.write()` of the wrapped object by encoding the passed
    value and passing the result to the wrapped object's `.write()` method.
    """
    # pylint: disable=too-few-public-methods
    def __init__(self, wrapped, encoding):
        object.__setattr__(self, '_wrapped', wrapped)
        object.__setattr__(self, 'encoding', encoding)

    def write(self, s):
        """
        Encode `s` and pass to the wrapped object's `.write()` method.
        """
        return getattr(self, '_wrapped').write(s.encode(getattr(self, 'encoding')))

    def __getattr__(self, name):
        return getattr(self._wrapped, name)

    def __setattr__(self, name, value): # pragma: no cover
        return setattr(self._wrapped, name, value)


def _is_utf(encoding):
    try:
        u'\u2588\u2589'.encode(encoding)
    except UnicodeEncodeError:  # pragma: no cover
        return False
    except Exception:  # pragma: no cover
        try:
            return encoding.lower().startswith('utf-') or ('U8' == encoding)
        except:
            return False
    else:
        return True


def _supports_unicode(fp):
    try:
        return _is_utf(fp.encoding)
    except AttributeError:
        return False


def _is_ascii(s):
    if isinstance(s, str):
        for c in s:
            if ord(c) > 255:
                return False
        return True
    return _supports_unicode(s)


def _environ_cols_wrapper():  # pragma: no cover
    """
    Return a function which gets width and height of console
    (linux,osx,windows,cygwin).
    """
    _environ_cols = None
    if IS_WIN:
        _environ_cols = _environ_cols_windows
        if _environ_cols is None:
            _environ_cols = _environ_cols_tput
    if IS_NIX:
        _environ_cols = _environ_cols_linux
    return _environ_cols


def _environ_cols_windows(fp):  # pragma: no cover
    try:
        from ctypes import windll, create_string_buffer
        import struct
        from sys import stdin, stdout

        io_handle = -12  # assume stderr
        if fp == stdin:
            io_handle = -10
        elif fp == stdout:
            io_handle = -11

        h = windll.kernel32.GetStdHandle(io_handle)
        csbi = create_string_buffer(22)
        res = windll.kernel32.GetConsoleScreenBufferInfo(h, csbi)
        if res:
            (_bufx, _bufy, _curx, _cury, _wattr, left, _top, right, _bottom,
             _maxx, _maxy) = struct.unpack("hhhhHhhhhhh", csbi.raw)
            # nlines = bottom - top + 1
            return right - left  # +1
    except:
        pass
    return None


def _environ_cols_tput(*_):  # pragma: no cover
    """cygwin xterm (windows)"""
    try:
        import shlex
        cols = int(subprocess.check_call(shlex.split('tput cols')))
        # rows = int(subprocess.check_call(shlex.split('tput lines')))
        return cols
    except:
        pass
    return None


def _environ_cols_linux(fp):  # pragma: no cover

    try:
        from termios import TIOCGWINSZ
        from fcntl import ioctl
        from array import array
    except ImportError:
        return None
    else:
        try:
            return array('h', ioctl(fp, TIOCGWINSZ, '\0' * 8))[1]
        except:
            try:
                return int(os.environ["COLUMNS"]) - 1
            except KeyError:
                return None


def _term_move_up():  # pragma: no cover
    return '' if (os.name == 'nt') and (colorama is None) else '\x1b[A'