# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""
Utilities for console input and output.
"""
import codecs
import locale
import math
import multiprocessing
import os
import re
import struct
import sys
import threading
import time
# concurrent.futures imports moved inside functions using them to avoid
# import failure when running in pyodide/Emscripten
try:
import fcntl
import signal
import termios
_CAN_RESIZE_TERMINAL = True
except ImportError:
_CAN_RESIZE_TERMINAL = False
from astropy import conf
from .decorators import classproperty
from .misc import isiterable
__all__ = [
"isatty",
"color_print",
"human_time",
"human_file_size",
"ProgressBar",
"Spinner",
"print_code_line",
"ProgressBarOrSpinner",
"terminal_size",
]
_DEFAULT_ENCODING = "utf-8"
class _IPython:
"""Singleton class given access to IPython streams, etc."""
@classproperty
def get_ipython(cls):
try:
from IPython import get_ipython
except ImportError:
pass
return get_ipython
@classproperty
def OutStream(cls):
if not hasattr(cls, "_OutStream"):
cls._OutStream = None
try:
cls.get_ipython()
except NameError:
return None
try:
from ipykernel.iostream import OutStream
except ImportError:
try:
from IPython.zmq.iostream import OutStream
except ImportError:
from IPython import version_info
if version_info[0] >= 4:
return None
try:
from IPython.kernel.zmq.iostream import OutStream
except ImportError:
return None
cls._OutStream = OutStream
return cls._OutStream
@classproperty
def ipyio(cls):
if not hasattr(cls, "_ipyio"):
try:
from IPython.utils import io
except ImportError:
cls._ipyio = None
else:
cls._ipyio = io
return cls._ipyio
@classmethod
def get_stream(cls, stream):
return getattr(cls.ipyio, stream)
def _get_stdout(stderr=False):
"""
This utility function contains the logic to determine what streams to use
by default for standard out/err.
Typically this will just return `sys.stdout`, but it contains additional
logic for use in IPython on Windows to determine the correct stream to use
(usually ``IPython.util.io.stdout`` but only if sys.stdout is a TTY).
"""
if stderr:
stream = "stderr"
else:
stream = "stdout"
sys_stream = getattr(sys, stream)
return sys_stream
[docs]def isatty(file):
"""
Returns `True` if ``file`` is a tty.
Most built-in Python file-like objects have an `isatty` member,
but some user-defined types may not, so this assumes those are not
ttys.
"""
if (
multiprocessing.current_process().name != "MainProcess"
or threading.current_thread().name != "MainThread"
):
return False
if hasattr(file, "isatty"):
return file.isatty()
if _IPython.OutStream is None or (not isinstance(file, _IPython.OutStream)):
return False
# File is an IPython OutStream. Check whether:
# - File name is 'stdout'; or
# - File wraps a Console
if getattr(file, "name", None) == "stdout":
return True
if hasattr(file, "stream"):
# FIXME: pyreadline has no had new release since 2015, drop it when
# IPython minversion is 5.x.
# On Windows, in IPython 2 the standard I/O streams will wrap
# pyreadline.Console objects if pyreadline is available; this should
# be considered a TTY.
try:
from pyreadline.console import Console as PyreadlineConsole
except ImportError:
return False
return isinstance(file.stream, PyreadlineConsole)
return False
[docs]def terminal_size(file=None):
"""
Returns a tuple (height, width) containing the height and width of
the terminal.
This function will look for the width in height in multiple areas
before falling back on the width and height in astropy's
configuration.
"""
if file is None:
file = _get_stdout()
try:
s = struct.pack("HHHH", 0, 0, 0, 0)
x = fcntl.ioctl(file, termios.TIOCGWINSZ, s)
(lines, width, xpixels, ypixels) = struct.unpack("HHHH", x)
if lines > 12:
lines -= 6
if width > 10:
width -= 1
if lines <= 0 or width <= 0:
raise Exception("unable to get terminal size")
return (lines, width)
except Exception:
try:
# see if POSIX standard variables will work
return (int(os.environ.get("LINES")), int(os.environ.get("COLUMNS")))
except TypeError:
# fall back on configuration variables, or if not
# set, (25, 80)
lines = conf.max_lines
width = conf.max_width
if lines is None:
lines = 25
if width is None:
width = 80
return lines, width
def _color_text(text, color):
"""
Returns a string wrapped in ANSI color codes for coloring the
text in a terminal::
colored_text = color_text('Here is a message', 'blue')
This won't actually effect the text until it is printed to the
terminal.
Parameters
----------
text : str
The string to return, bounded by the color codes.
color : str
An ANSI terminal color name. Must be one of:
black, red, green, brown, blue, magenta, cyan, lightgrey,
default, darkgrey, lightred, lightgreen, yellow, lightblue,
lightmagenta, lightcyan, white, or '' (the empty string).
"""
color_mapping = {
"black": "0;30",
"red": "0;31",
"green": "0;32",
"brown": "0;33",
"blue": "0;34",
"magenta": "0;35",
"cyan": "0;36",
"lightgrey": "0;37",
"default": "0;39",
"darkgrey": "1;30",
"lightred": "1;31",
"lightgreen": "1;32",
"yellow": "1;33",
"lightblue": "1;34",
"lightmagenta": "1;35",
"lightcyan": "1;36",
"white": "1;37",
}
if sys.platform == "win32" and _IPython.OutStream is None:
# On Windows do not colorize text unless in IPython
return text
color_code = color_mapping.get(color, "0;39")
return f"\033[{color_code}m{text}\033[0m"
def _decode_preferred_encoding(s):
"""Decode the supplied byte string using the preferred encoding
for the locale (`locale.getpreferredencoding`) or, if the default encoding
is invalid, fall back first on utf-8, then on latin-1 if the message cannot
be decoded with utf-8.
"""
enc = locale.getpreferredencoding()
try:
try:
return s.decode(enc)
except LookupError:
enc = _DEFAULT_ENCODING
return s.decode(enc)
except UnicodeDecodeError:
return s.decode("latin-1")
def _write_with_fallback(s, write, fileobj):
"""Write the supplied string with the given write function like
``write(s)``, but use a writer for the locale's preferred encoding in case
of a UnicodeEncodeError. Failing that attempt to write with 'utf-8' or
'latin-1'.
"""
try:
write(s)
return write
except UnicodeEncodeError:
# Let's try the next approach...
pass
enc = locale.getpreferredencoding()
try:
Writer = codecs.getwriter(enc)
except LookupError:
Writer = codecs.getwriter(_DEFAULT_ENCODING)
f = Writer(fileobj)
write = f.write
try:
write(s)
return write
except UnicodeEncodeError:
Writer = codecs.getwriter("latin-1")
f = Writer(fileobj)
write = f.write
# If this doesn't work let the exception bubble up; I'm out of ideas
write(s)
return write
[docs]def color_print(*args, end="\n", **kwargs):
"""
Prints colors and styles to the terminal uses ANSI escape
sequences.
::
color_print('This is the color ', 'default', 'GREEN', 'green')
Parameters
----------
positional args : str
The positional arguments come in pairs (*msg*, *color*), where
*msg* is the string to display and *color* is the color to
display it in.
*color* is an ANSI terminal color name. Must be one of:
black, red, green, brown, blue, magenta, cyan, lightgrey,
default, darkgrey, lightred, lightgreen, yellow, lightblue,
lightmagenta, lightcyan, white, or '' (the empty string).
file : writable file-like, optional
Where to write to. Defaults to `sys.stdout`. If file is not
a tty (as determined by calling its `isatty` member, if one
exists), no coloring will be included.
end : str, optional
The ending of the message. Defaults to ``\\n``. The end will
be printed after resetting any color or font state.
"""
file = kwargs.get("file", _get_stdout())
write = file.write
if isatty(file) and conf.use_color:
for i in range(0, len(args), 2):
msg = args[i]
if i + 1 == len(args):
color = ""
else:
color = args[i + 1]
if color:
msg = _color_text(msg, color)
# Some file objects support writing unicode sensibly on some Python
# versions; if this fails try creating a writer using the locale's
# preferred encoding. If that fails too give up.
write = _write_with_fallback(msg, write, file)
write(end)
else:
for i in range(0, len(args), 2):
msg = args[i]
write(msg)
write(end)
def strip_ansi_codes(s):
"""
Remove ANSI color codes from the string.
"""
return re.sub("\033\\[([0-9]+)(;[0-9]+)*m", "", s)
[docs]def human_time(seconds):
"""
Returns a human-friendly time string that is always exactly 6
characters long.
Depending on the number of seconds given, can be one of::
1w 3d
2d 4h
1h 5m
1m 4s
15s
Will be in color if console coloring is turned on.
Parameters
----------
seconds : int
The number of seconds to represent
Returns
-------
time : str
A human-friendly representation of the given number of seconds
that is always exactly 6 characters.
"""
units = [
("y", 60 * 60 * 24 * 7 * 52),
("w", 60 * 60 * 24 * 7),
("d", 60 * 60 * 24),
("h", 60 * 60),
("m", 60),
("s", 1),
]
seconds = int(seconds)
if seconds < 60:
return f" {seconds:2d}s"
for i in range(len(units) - 1):
unit1, limit1 = units[i]
unit2, limit2 = units[i + 1]
if seconds >= limit1:
return "{:2d}{}{:2d}{}".format(
seconds // limit1, unit1, (seconds % limit1) // limit2, unit2
)
return " ~inf"
[docs]def human_file_size(size):
"""
Returns a human-friendly string representing a file size
that is 2-4 characters long.
For example, depending on the number of bytes given, can be one
of::
256b
64k
1.1G
Parameters
----------
size : int
The size of the file (in bytes)
Returns
-------
size : str
A human-friendly representation of the size of the file
"""
if hasattr(size, "unit"):
# Import units only if necessary because the import takes a
# significant time [#4649]
from astropy import units as u
size = u.Quantity(size, u.byte).value
suffixes = " kMGTPEZY"
if size == 0:
num_scale = 0
else:
num_scale = int(math.floor(math.log(size) / math.log(1000)))
if num_scale > 7:
suffix = "?"
else:
suffix = suffixes[num_scale]
num_scale = int(math.pow(1000, num_scale))
value = size / num_scale
str_value = str(value)
if suffix == " ":
str_value = str_value[: str_value.index(".")]
elif str_value[2] == ".":
str_value = str_value[:2]
else:
str_value = str_value[:3]
return f"{str_value:>3s}{suffix}"
class _mapfunc:
"""
A function wrapper to support ProgressBar.map().
"""
def __init__(self, func):
self._func = func
def __call__(self, i_arg):
i, arg = i_arg
return i, self._func(arg)
[docs]class ProgressBar:
"""
A class to display a progress bar in the terminal.
It is designed to be used either with the ``with`` statement::
with ProgressBar(len(items)) as bar:
for item in enumerate(items):
bar.update()
or as a generator::
for item in ProgressBar(items):
item.process()
"""
def __init__(self, total_or_items, ipython_widget=False, file=None):
"""
Parameters
----------
total_or_items : int or sequence
If an int, the number of increments in the process being
tracked. If a sequence, the items to iterate over.
ipython_widget : bool, optional
If `True`, the progress bar will display as an IPython
notebook widget.
file : writable file-like, optional
The file to write the progress bar to. Defaults to
`sys.stdout`. If ``file`` is not a tty (as determined by
calling its `isatty` member, if any, or special case hacks
to detect the IPython console), the progress bar will be
completely silent.
"""
if file is None:
file = _get_stdout()
if not ipython_widget and not isatty(file):
self.update = self._silent_update
self._silent = True
else:
self._silent = False
if isiterable(total_or_items):
self._items = iter(total_or_items)
self._total = len(total_or_items)
else:
try:
self._total = int(total_or_items)
except TypeError:
raise TypeError("First argument must be int or sequence")
else:
self._items = iter(range(self._total))
self._file = file
self._start_time = time.time()
self._human_total = human_file_size(self._total)
self._ipython_widget = ipython_widget
self._signal_set = False
if not ipython_widget:
self._should_handle_resize = _CAN_RESIZE_TERMINAL and self._file.isatty()
self._handle_resize()
if self._should_handle_resize:
signal.signal(signal.SIGWINCH, self._handle_resize)
self._signal_set = True
self.update(0)
def _handle_resize(self, signum=None, frame=None):
terminal_width = terminal_size(self._file)[1]
self._bar_length = terminal_width - 37
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
if not self._silent:
if exc_type is None:
self.update(self._total)
self._file.write("\n")
self._file.flush()
if self._signal_set:
signal.signal(signal.SIGWINCH, signal.SIG_DFL)
def __iter__(self):
return self
def __next__(self):
try:
rv = next(self._items)
except StopIteration:
self.__exit__(None, None, None)
raise
else:
self.update()
return rv
[docs] def update(self, value=None):
"""
Update progress bar via the console or notebook accordingly.
"""
# Update self.value
if value is None:
value = self._current_value + 1
self._current_value = value
# Choose the appropriate environment
if self._ipython_widget:
self._update_ipython_widget(value)
else:
self._update_console(value)
def _update_console(self, value=None):
"""
Update the progress bar to the given value (out of the total
given to the constructor).
"""
if self._total == 0:
frac = 1.0
else:
frac = float(value) / float(self._total)
file = self._file
write = file.write
if frac > 1:
bar_fill = int(self._bar_length)
else:
bar_fill = int(float(self._bar_length) * frac)
write("\r|")
color_print("=" * bar_fill, "blue", file=file, end="")
if bar_fill < self._bar_length:
color_print(">", "green", file=file, end="")
write("-" * (self._bar_length - bar_fill - 1))
write("|")
if value >= self._total:
t = time.time() - self._start_time
prefix = " "
elif value <= 0:
t = None
prefix = ""
else:
t = ((time.time() - self._start_time) * (1.0 - frac)) / frac
prefix = " ETA "
write(f" {human_file_size(value):>4s}/{self._human_total:>4s}")
write(f" ({frac:>6.2%})")
write(prefix)
if t is not None:
write(human_time(t))
self._file.flush()
def _update_ipython_widget(self, value=None):
"""
Update the progress bar to the given value (out of a total
given to the constructor).
This method is for use in the IPython notebook 2+.
"""
# Create and display an empty progress bar widget,
# if none exists.
if not hasattr(self, "_widget"):
# Import only if an IPython widget, i.e., widget in iPython NB
from IPython import version_info
if version_info[0] < 4:
from IPython.html import widgets
self._widget = widgets.FloatProgressWidget()
else:
_IPython.get_ipython()
from ipywidgets import widgets
self._widget = widgets.FloatProgress()
from IPython.display import display
display(self._widget)
self._widget.value = 0
# Calculate percent completion, and update progress bar
frac = value / self._total
self._widget.value = frac * 100
self._widget.description = f" ({frac:>6.2%})"
def _silent_update(self, value=None):
pass
[docs] @classmethod
def map(
cls,
function,
items,
multiprocess=False,
file=None,
step=100,
ipython_widget=False,
multiprocessing_start_method=None,
):
"""Map function over items while displaying a progress bar with percentage complete.
The map operation may run in arbitrary order on the items, but the results are
returned in sequential order.
::
def work(i):
print(i)
ProgressBar.map(work, range(50))
Parameters
----------
function : function
Function to call for each step
items : sequence
Sequence where each element is a tuple of arguments to pass to
*function*.
multiprocess : bool, int, optional
If `True`, use the `multiprocessing` module to distribute each task
to a different processor core. If a number greater than 1, then use
that number of cores.
ipython_widget : bool, optional
If `True`, the progress bar will display as an IPython
notebook widget.
file : writable file-like, optional
The file to write the progress bar to. Defaults to
`sys.stdout`. If ``file`` is not a tty (as determined by
calling its `isatty` member, if any), the scrollbar will
be completely silent.
step : int, optional
Update the progress bar at least every *step* steps (default: 100).
If ``multiprocess`` is `True`, this will affect the size
of the chunks of ``items`` that are submitted as separate tasks
to the process pool. A large step size may make the job
complete faster if ``items`` is very long.
multiprocessing_start_method : str, optional
Useful primarily for testing; if in doubt leave it as the default.
When using multiprocessing, certain anomalies occur when starting
processes with the "spawn" method (the only option on Windows);
other anomalies occur with the "fork" method (the default on
Linux).
"""
if multiprocess:
function = _mapfunc(function)
items = list(enumerate(items))
results = cls.map_unordered(
function,
items,
multiprocess=multiprocess,
file=file,
step=step,
ipython_widget=ipython_widget,
multiprocessing_start_method=multiprocessing_start_method,
)
if multiprocess:
_, results = zip(*sorted(results))
results = list(results)
return results
[docs] @classmethod
def map_unordered(
cls,
function,
items,
multiprocess=False,
file=None,
step=100,
ipython_widget=False,
multiprocessing_start_method=None,
):
"""Map function over items, reporting the progress.
Does a `map` operation while displaying a progress bar with
percentage complete. The map operation may run on arbitrary order
on the items, and the results may be returned in arbitrary order.
::
def work(i):
print(i)
ProgressBar.map(work, range(50))
Parameters
----------
function : function
Function to call for each step
items : sequence
Sequence where each element is a tuple of arguments to pass to
*function*.
multiprocess : bool, int, optional
If `True`, use the `multiprocessing` module to distribute each task
to a different processor core. If a number greater than 1, then use
that number of cores.
ipython_widget : bool, optional
If `True`, the progress bar will display as an IPython
notebook widget.
file : writable file-like, optional
The file to write the progress bar to. Defaults to
`sys.stdout`. If ``file`` is not a tty (as determined by
calling its `isatty` member, if any), the scrollbar will
be completely silent.
step : int, optional
Update the progress bar at least every *step* steps (default: 100).
If ``multiprocess`` is `True`, this will affect the size
of the chunks of ``items`` that are submitted as separate tasks
to the process pool. A large step size may make the job
complete faster if ``items`` is very long.
multiprocessing_start_method : str, optional
Useful primarily for testing; if in doubt leave it as the default.
When using multiprocessing, certain anomalies occur when starting
processes with the "spawn" method (the only option on Windows);
other anomalies occur with the "fork" method (the default on
Linux).
"""
# concurrent.futures import here to avoid import failure when running
# in pyodide/Emscripten
from concurrent.futures import ProcessPoolExecutor, as_completed
results = []
if file is None:
file = _get_stdout()
with cls(len(items), ipython_widget=ipython_widget, file=file) as bar:
if bar._ipython_widget:
chunksize = step
else:
default_step = max(int(float(len(items)) / bar._bar_length), 1)
chunksize = min(default_step, step)
if not multiprocess or multiprocess < 1:
for i, item in enumerate(items):
results.append(function(item))
if (i % chunksize) == 0:
bar.update(i)
else:
ctx = multiprocessing.get_context(multiprocessing_start_method)
kwargs = dict(mp_context=ctx)
with ProcessPoolExecutor(
max_workers=(
int(multiprocess) if multiprocess is not True else None
),
**kwargs,
) as p:
for i, f in enumerate(
as_completed(p.submit(function, item) for item in items)
):
bar.update(i)
results.append(f.result())
return results
[docs]class Spinner:
"""
A class to display a spinner in the terminal.
It is designed to be used with the ``with`` statement::
with Spinner("Reticulating splines", "green") as s:
for item in enumerate(items):
s.update()
"""
_default_unicode_chars = "◓◑◒◐"
_default_ascii_chars = "-/|\\"
def __init__(self, msg, color="default", file=None, step=1, chars=None):
"""
Parameters
----------
msg : str
The message to print
color : str, optional
An ANSI terminal color name. Must be one of: black, red,
green, brown, blue, magenta, cyan, lightgrey, default,
darkgrey, lightred, lightgreen, yellow, lightblue,
lightmagenta, lightcyan, white.
file : writable file-like, optional
The file to write the spinner to. Defaults to
`sys.stdout`. If ``file`` is not a tty (as determined by
calling its `isatty` member, if any, or special case hacks
to detect the IPython console), the spinner will be
completely silent.
step : int, optional
Only update the spinner every *step* steps
chars : str, optional
The character sequence to use for the spinner
"""
if file is None:
file = _get_stdout()
self._msg = msg
self._color = color
self._file = file
self._step = step
if chars is None:
if conf.unicode_output:
chars = self._default_unicode_chars
else:
chars = self._default_ascii_chars
self._chars = chars
self._silent = not isatty(file)
if self._silent:
self._iter = self._silent_iterator()
else:
self._iter = self._iterator()
def _iterator(self):
chars = self._chars
index = 0
file = self._file
write = file.write
flush = file.flush
try_fallback = True
while True:
write("\r")
color_print(self._msg, self._color, file=file, end="")
write(" ")
try:
if try_fallback:
write = _write_with_fallback(chars[index], write, file)
else:
write(chars[index])
except UnicodeError:
# If even _write_with_fallback failed for any reason just give
# up on trying to use the unicode characters
chars = self._default_ascii_chars
write(chars[index])
try_fallback = False # No good will come of using this again
flush()
yield
for i in range(self._step):
yield
index = (index + 1) % len(chars)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
file = self._file
write = file.write
flush = file.flush
if not self._silent:
write("\r")
color_print(self._msg, self._color, file=file, end="")
if exc_type is None:
color_print(" [Done]", "green", file=file)
else:
color_print(" [Failed]", "red", file=file)
flush()
def __iter__(self):
return self
def __next__(self):
next(self._iter)
[docs] def update(self, value=None):
"""Update the spin wheel in the terminal.
Parameters
----------
value : int, optional
Ignored (present just for compatibility with `ProgressBar.update`).
"""
next(self)
def _silent_iterator(self):
color_print(self._msg, self._color, file=self._file, end="")
self._file.flush()
while True:
yield
[docs]class ProgressBarOrSpinner:
"""
A class that displays either a `ProgressBar` or `Spinner`
depending on whether the total size of the operation is
known or not.
It is designed to be used with the ``with`` statement::
if file.has_length():
length = file.get_length()
else:
length = None
bytes_read = 0
with ProgressBarOrSpinner(length) as bar:
while file.read(blocksize):
bytes_read += blocksize
bar.update(bytes_read)
"""
def __init__(self, total, msg, color="default", file=None):
"""
Parameters
----------
total : int or None
If an int, the number of increments in the process being
tracked and a `ProgressBar` is displayed. If `None`, a
`Spinner` is displayed.
msg : str
The message to display above the `ProgressBar` or
alongside the `Spinner`.
color : str, optional
The color of ``msg``, if any. Must be an ANSI terminal
color name. Must be one of: black, red, green, brown,
blue, magenta, cyan, lightgrey, default, darkgrey,
lightred, lightgreen, yellow, lightblue, lightmagenta,
lightcyan, white.
file : writable file-like, optional
The file to write the to. Defaults to `sys.stdout`. If
``file`` is not a tty (as determined by calling its `isatty`
member, if any), only ``msg`` will be displayed: the
`ProgressBar` or `Spinner` will be silent.
"""
if file is None:
file = _get_stdout()
if total is None or not isatty(file):
self._is_spinner = True
self._obj = Spinner(msg, color=color, file=file)
else:
self._is_spinner = False
color_print(msg, color, file=file)
self._obj = ProgressBar(total, file=file)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
return self._obj.__exit__(exc_type, exc_value, traceback)
[docs] def update(self, value):
"""
Update the progress bar to the given value (out of the total
given to the constructor.
"""
self._obj.update(value)
[docs]def print_code_line(line, col=None, file=None, tabwidth=8, width=70):
"""
Prints a line of source code, highlighting a particular character
position in the line. Useful for displaying the context of error
messages.
If the line is more than ``width`` characters, the line is truncated
accordingly and '…' characters are inserted at the front and/or
end.
It looks like this::
there_is_a_syntax_error_here :
^
Parameters
----------
line : unicode
The line of code to display
col : int, optional
The character in the line to highlight. ``col`` must be less
than ``len(line)``.
file : writable file-like, optional
Where to write to. Defaults to `sys.stdout`.
tabwidth : int, optional
The number of spaces per tab (``'\\t'``) character. Default
is 8. All tabs will be converted to spaces to ensure that the
caret lines up with the correct column.
width : int, optional
The width of the display, beyond which the line will be
truncated. Defaults to 70 (this matches the default in the
standard library's `textwrap` module).
"""
if file is None:
file = _get_stdout()
if conf.unicode_output:
ellipsis = "…"
else:
ellipsis = "..."
write = file.write
if col is not None:
if col >= len(line):
raise ValueError("col must be less the the line length.")
ntabs = line[:col].count("\t")
col += ntabs * (tabwidth - 1)
line = line.rstrip("\n")
line = line.replace("\t", " " * tabwidth)
if col is not None and col > width:
new_col = min(width // 2, len(line) - col)
offset = col - new_col
line = line[offset + len(ellipsis) :]
width -= len(ellipsis)
new_col = col
col -= offset
color_print(ellipsis, "darkgrey", file=file, end="")
if len(line) > width:
write(line[: width - len(ellipsis)])
color_print(ellipsis, "darkgrey", file=file)
else:
write(line)
write("\n")
if col is not None:
write(" " * col)
color_print("^", "red", file=file)
# The following four Getch* classes implement unbuffered character reading from
# stdin on Windows, linux, MacOSX. This is taken directly from ActiveState
# Code Recipes:
# http://code.activestate.com/recipes/134892-getch-like-unbuffered-character-reading-from-stdin/
#
class Getch:
"""Get a single character from standard input without screen echo.
Returns
-------
char : str (one character)
"""
def __init__(self):
try:
self.impl = _GetchWindows()
except ImportError:
try:
self.impl = _GetchMacCarbon()
except (ImportError, AttributeError):
self.impl = _GetchUnix()
def __call__(self):
return self.impl()
class _GetchUnix:
def __init__(self):
import sys # noqa: F401
# import termios now or else you'll get the Unix
# version on the Mac
import termios # noqa: F401
import tty # noqa: F401
def __call__(self):
import sys
import termios
import tty
fd = sys.stdin.fileno()
old_settings = termios.tcgetattr(fd)
try:
tty.setraw(sys.stdin.fileno())
ch = sys.stdin.read(1)
finally:
termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
return ch
class _GetchWindows:
def __init__(self):
import msvcrt # noqa: F401
def __call__(self):
import msvcrt
return msvcrt.getch()
class _GetchMacCarbon:
"""
A function which returns the current ASCII key that is down;
if no ASCII key is down, the null string is returned. The
page http://www.mactech.com/macintosh-c/chap02-1.html was
very helpful in figuring out how to do this.
"""
def __init__(self):
import Carbon
Carbon.Evt # see if it has this (in Unix, it doesn't)
def __call__(self):
import Carbon
if Carbon.Evt.EventAvail(0x0008)[0] == 0: # 0x0008 is the keyDownMask
return ""
else:
#
# The event contains the following info:
# (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
#
# The message (msg) contains the ASCII char which is
# extracted with the 0x000000FF charCodeMask; this
# number is converted to an ASCII character with chr() and
# returned
#
(what, msg, when, where, mod) = Carbon.Evt.GetNextEvent(0x0008)[1]
return chr(msg & 0x000000FF)