411 lines
12 KiB
Python
411 lines
12 KiB
Python
# coding=utf-8
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#
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# Copyright (C) 2010 Nick Drobchenko, nick@cnc-club.ru
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# Copyright (C) 2005 Aaron Spike, aaron@ekips.org
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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#
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"""
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Basic common utility functions for calculated things
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"""
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from collections import OrderedDict, defaultdict
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import os
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import sys
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import random
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import re
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import math
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from argparse import ArgumentTypeError
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from itertools import tee, cycle
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import numpy as np
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ABORT_STATUS = -5
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(X, Y) = range(2)
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PY3 = sys.version_info[0] == 3
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# pylint: disable=line-too-long
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# Taken from https://www.w3.org/Graphics/SVG/1.1/paths.html#PathDataBNF
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DIGIT_REX_PART = r"[0-9]"
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DIGIT_SEQUENCE_REX_PART = rf"(?:{DIGIT_REX_PART}+)"
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INTEGER_CONSTANT_REX_PART = DIGIT_SEQUENCE_REX_PART
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SIGN_REX_PART = r"[+-]"
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EXPONENT_REX_PART = rf"(?:[eE]{SIGN_REX_PART}?{DIGIT_SEQUENCE_REX_PART})"
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FRACTIONAL_CONSTANT_REX_PART = rf"(?:{DIGIT_SEQUENCE_REX_PART}?\.{DIGIT_SEQUENCE_REX_PART}|{DIGIT_SEQUENCE_REX_PART}\.)"
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FLOATING_POINT_CONSTANT_REX_PART = rf"(?:{FRACTIONAL_CONSTANT_REX_PART}{EXPONENT_REX_PART}?|{DIGIT_SEQUENCE_REX_PART}{EXPONENT_REX_PART})"
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NUMBER_REX = re.compile(
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rf"(?:{SIGN_REX_PART}?{FLOATING_POINT_CONSTANT_REX_PART}|{SIGN_REX_PART}?{INTEGER_CONSTANT_REX_PART})"
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)
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# pylint: enable=line-too-long
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def _pythonpath():
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for pth in os.environ.get("PYTHONPATH", "").split(":"):
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if os.path.isdir(pth):
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yield pth
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def get_user_directory():
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"""Return the user directory where extensions are stored.
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.. versionadded:: 1.1"""
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if "INKSCAPE_PROFILE_DIR" in os.environ:
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return os.path.abspath(
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os.path.expanduser(
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os.path.join(os.environ["INKSCAPE_PROFILE_DIR"], "extensions")
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)
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)
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home = os.path.expanduser("~")
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for pth in _pythonpath():
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if pth.startswith(home):
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return pth
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return None
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def get_inkscape_directory():
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"""Return the system directory where inkscape's core is.
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.. versionadded:: 1.1"""
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for pth in _pythonpath():
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if os.path.isdir(os.path.join(pth, "inkex")):
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return pth
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raise ValueError("Unable to determine the location of Inkscape")
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class KeyDict(dict):
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"""
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A normal dictionary, except asking for anything not in the dictionary
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always returns the key itself. This is used for translation dictionaries.
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"""
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def __getitem__(self, key):
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try:
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return super().__getitem__(key)
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except KeyError:
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return key
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def parse_percent(val: str):
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"""Parse strings that are either values (i.e., '3.14159') or percentages
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(i.e. '75%') to a float.
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.. versionadded:: 1.2"""
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val = val.strip()
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if val.endswith("%"):
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return float(val[:-1]) / 100
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return float(val)
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def Boolean(value):
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"""ArgParser function to turn a boolean string into a python boolean"""
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if value.upper() == "TRUE":
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return True
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if value.upper() == "FALSE":
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return False
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return None
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def to_bytes(content):
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"""Ensures the content is bytes
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.. versionadded:: 1.1"""
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if isinstance(content, bytes):
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return content
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return str(content).encode("utf8")
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def debug(what):
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"""Print debug message if debugging is switched on"""
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errormsg(what)
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return what
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def do_nothing(*args, **kwargs): # pylint: disable=unused-argument
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"""A blank function to do nothing
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.. versionadded:: 1.1"""
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def errormsg(msg):
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"""Intended for end-user-visible error messages.
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(Currently just writes to stderr with an appended newline, but could do
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something better in future: e.g. could add markup to distinguish error
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messages from status messages or debugging output.)
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Note that this should always be combined with translation::
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import inkex
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...
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inkex.errormsg(_("This extension requires two selected paths."))
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"""
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try:
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sys.stderr.write(msg)
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except TypeError:
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sys.stderr.write(str(msg))
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except UnicodeEncodeError:
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# Python 2:
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# Fallback for cases where sys.stderr.encoding is not Unicode.
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# Python 3:
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# This will not work as write() does not accept byte strings, but AFAIK
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# we should never reach this point as the default error handler is
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# 'backslashreplace'.
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# This will be None by default if stderr is piped, so use ASCII as a
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# last resort.
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encoding = sys.stderr.encoding or "ascii"
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sys.stderr.write(msg.encode(encoding, "backslashreplace"))
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# Write '\n' separately to avoid dealing with different string types.
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sys.stderr.write("\n")
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class AbortExtension(Exception):
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"""Raised to print a message to the user without backtrace"""
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class DependencyError(NotImplementedError):
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"""Raised when we need an external python module that isn't available"""
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class FragmentError(Exception):
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"""Raised when trying to do rooty things on an xml fragment"""
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def to(kind): # pylint: disable=invalid-name
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"""
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Decorator which will turn a generator into a list, tuple or other object type.
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"""
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def _inner(call):
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def _outer(*args, **kw):
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return kind(call(*args, **kw))
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return _outer
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return _inner
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def strargs(string, kind=float):
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"""Returns a list of floats from a string
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.. versionchanged:: 1.1
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also splits at -(minus) signs by adding a space in front of the - sign
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.. versionchanged:: 1.2
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Full support for the `SVG Path data BNF
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<https://www.w3.org/Graphics/SVG/1.1/paths.html#PathDataBNF>`_
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"""
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return [kind(val) for val in NUMBER_REX.findall(string)]
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class classproperty: # pylint: disable=invalid-name, too-few-public-methods
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"""Combine classmethod and property decorators"""
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def __init__(self, func):
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self.func = func
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def __get__(self, obj, owner):
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return self.func(owner)
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def filename_arg(name):
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"""Existing file to read or option used in script arguments"""
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filename = os.path.abspath(os.path.expanduser(name))
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if not os.path.isfile(filename):
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raise ArgumentTypeError(f"File not found: {name}")
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return filename
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def pairwise(iterable, start=True):
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"Iterate over a list with overlapping pairs (see itertools recipes)"
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first, then = tee(iterable)
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starter = [(None, next(then, None))]
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if not start:
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starter = []
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return starter + list(zip(first, then))
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def circular_pairwise(l):
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"""Iterate over a list with overlapping pairs in a periodic way, i.e.
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[1, 2, 3] -> [(1, 2), (2, 3), (3, 1)]
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..versionadded:: 1.3.1"""
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second = cycle(l)
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next(second)
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return zip(l, second)
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EVAL_GLOBALS = {}
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EVAL_GLOBALS.update(random.__dict__)
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EVAL_GLOBALS.update(math.__dict__)
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def math_eval(function, variable="x"):
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"""Interpret a function string. All functions from math and random may be used.
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.. versionadded:: 1.1
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Returns:
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a lambda expression if sucessful; otherwise None.
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"""
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try:
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if function != "":
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return eval(
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f"lambda {variable}: " + (function.strip('"') or "t"), EVAL_GLOBALS, {}
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)
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# handle incomplete/invalid function gracefully
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except SyntaxError:
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pass
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return None
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def is_number(string):
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"""Checks if a value is a number
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.. versionadded:: 1.2"""
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try:
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float(string)
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return True
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except ValueError:
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return False
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def rational_limit(f: np.poly1d, g: np.poly1d, t0):
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"""Computes the limit of the rational function (f/g)(t)
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as t approaches t0.
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.. versionadded:: 1.4"""
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assert g != np.poly1d([0])
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if g(t0) != 0:
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return f(t0) / g(t0)
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elif f(t0) == 0:
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return rational_limit(f.deriv(), g.deriv(), t0)
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else:
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raise ValueError("Limit does not exist.")
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def callback_method(func):
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def notify(self, *args, **kwargs):
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result = func(self, *args, **kwargs)
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self._callback()
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return result
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return notify
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class NotifyList(list):
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"""A list that calls a callback after it is modified
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(to notify a parent about the modification).
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Modified from https://stackoverflow.com/a/13259435/3298143
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.. versionadded:: 1.4"""
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extend = callback_method(list.extend)
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append = callback_method(list.append)
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remove = callback_method(list.remove)
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pop = callback_method(list.pop)
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__delitem__ = callback_method(list.__delitem__)
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__setitem__ = callback_method(list.__setitem__)
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__iadd__ = callback_method(list.__iadd__)
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__imul__ = callback_method(list.__imul__)
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def __getitem__(self, item):
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"""Ensure that slicing returns a list of the same datatype"""
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if isinstance(item, slice):
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return self.__class__(list.__getitem__(self, item))
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return list.__getitem__(self, item)
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def __init__(self, *args, callback=None):
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self.callback = None
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list.__init__(self, *args)
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self.callback = callback
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def _callback(self):
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if self.callback is not None:
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self.callback(self)
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def toggle(self, value):
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"""If exists, remove it, if not, add it"""
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value = str(value)
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if value in self:
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return self.remove(value)
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return self.append(value)
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class NotifyOrderedDict(OrderedDict):
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"""An OrderedDict that notifies a callback after a value is changed
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.. versionadded:: 1.4"""
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clear = callback_method(OrderedDict.clear)
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popitem = callback_method(OrderedDict.popitem)
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update = callback_method(OrderedDict.update)
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setdefault = callback_method(OrderedDict.setdefault)
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__setitem__ = callback_method(OrderedDict.__setitem__)
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__delitem__ = callback_method(OrderedDict.__delitem__)
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def __init__(self, *args, callback=None, **kwargs):
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self.callback = None
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super().__init__(*args, **kwargs)
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self.callback = callback
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def _callback(self):
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if self.callback is not None:
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self.callback(self)
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def pop(self, key, default=None):
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super().pop(key, default)
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# On Python < 3.11, pop internally calls __delitem__.
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# This does not happen in 3.11. To avoid
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# calling the callback twice, we need to check the Python version.
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if sys.version_info >= (3, 11):
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if self.callback is not None:
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self.callback(self)
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class NotifyDefaultDict(defaultdict):
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"""A defaultdict that notifies a callback after a value is changed
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.. versionadded:: 1.4"""
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clear = callback_method(defaultdict.clear)
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popitem = callback_method(defaultdict.popitem)
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update = callback_method(defaultdict.update)
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setdefault = callback_method(defaultdict.setdefault)
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__setitem__ = callback_method(defaultdict.__setitem__)
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__delitem__ = callback_method(defaultdict.__delitem__)
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def __init__(self, *args, callback=None, **kwargs):
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self.callback = None
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super().__init__(*args, **kwargs)
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self.callback = callback
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def _callback(self):
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if self.callback is not None:
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self.callback(self)
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def pop(self, key, default=None):
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super().pop(key, default)
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# On Python < 3.11, pop internally calls __delitem__.
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# This does not happen in 3.11. To avoid
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# calling the callback twice, we need to check the Python version.
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if sys.version_info >= (3, 11):
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if self.callback is not None:
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self.callback(self)
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