Source code for xonsh.built_ins

"""The xonsh built-ins.

Note that this module is named 'built_ins' so as not to be confused with the
special Python builtins module.
"""

import atexit
import builtins
import collections.abc as cabc
import contextlib
import inspect
import itertools
import os
import pathlib
import re
import signal
import sys
import types
import warnings
from ast import AST

from xonsh.lib.inspectors import Inspector
from xonsh.lib.lazyasd import lazyobject
from xonsh.platform import ON_POSIX
from xonsh.tools import (
    XonshCalledProcessError,
    XonshError,
    expand_path,
    globpath,
    print_color,
)

INSPECTOR = Inspector()

warnings.filterwarnings("once", category=DeprecationWarning)


@lazyobject
def AT_EXIT_SIGNALS():
    sigs = (
        signal.SIGABRT,
        signal.SIGFPE,
        signal.SIGILL,
        signal.SIGSEGV,
        signal.SIGTERM,
    )
    if ON_POSIX:
        sigs += (signal.SIGTSTP, signal.SIGQUIT, signal.SIGHUP)
    return sigs


[docs] def resetting_signal_handle(sig, f): """Sets a new signal handle that will automatically restore the old value once the new handle is finished. """ prev_signal_handler = signal.getsignal(sig) def new_signal_handler(s=None, frame=None): f(s, frame) signal.signal(sig, prev_signal_handler) if sig != 0: """ There is no immediate exiting here. The ``sys.exit()`` function raises a ``SystemExit`` exception. This exception must be caught and processed in the upstream code. """ sys.exit(sig) signal.signal(sig, new_signal_handler)
[docs] def helper(x, name=""): """Prints help about, and then returns that variable.""" name = name or getattr(x, "__name__", "") INSPECTOR.pinfo(x, oname=name, detail_level=0) return x
[docs] def superhelper(x, name=""): """Prints help about, and then returns that variable.""" name = name or getattr(x, "__name__", "") INSPECTOR.pinfo(x, oname=name, detail_level=1) return x
[docs] def reglob(path, parts=None, i=None): """Regular expression-based globbing.""" if parts is None: path = os.path.normpath(path) drive, tail = os.path.splitdrive(path) parts = tail.split(os.sep) d = os.sep if os.path.isabs(path) else "." d = os.path.join(drive, d) return reglob(d, parts, i=0) base = subdir = path if i == 0: if not os.path.isabs(base): base = "" elif len(parts) > 1: i += 1 try: regex = re.compile(parts[i]) except Exception as e: if isinstance(e, re.error) and str(e) == "nothing to repeat at position 0": raise XonshError( "Consider adding a leading '.' to your glob regex pattern." ) from e else: raise e files = os.listdir(subdir) files.sort() paths = [] i1 = i + 1 if i1 == len(parts): for f in files: p = os.path.join(base, f) if regex.fullmatch(f) is not None: paths.append(p) else: for f in files: p = os.path.join(base, f) if regex.fullmatch(f) is None or not os.path.isdir(p): continue paths += reglob(p, parts=parts, i=i1) return paths
[docs] def path_literal(s): s = expand_path(s) return pathlib.Path(s)
[docs] def regexsearch(s): s = expand_path(s) return reglob(s)
[docs] def globsearch(s): csc = XSH.env.get("CASE_SENSITIVE_COMPLETIONS") glob_sorted = XSH.env.get("GLOB_SORTED") dotglob = XSH.env.get("DOTGLOB") return globpath( s, ignore_case=(not csc), return_empty=True, sort_result=glob_sorted, include_dotfiles=dotglob, )
[docs] def pathsearch(func, s, pymode=False, pathobj=False): """ Takes a string and returns a list of file paths that match (regex, glob, or arbitrary search function). If pathobj=True, the return is a list of pathlib.Path objects instead of strings. """ if not callable(func) or len(inspect.signature(func).parameters) != 1: error = "%r is not a known path search function" raise XonshError(error % func) o = func(s) if pathobj and pymode: o = list(map(pathlib.Path, o)) no_match = [] if pymode else [s] return o if len(o) != 0 else no_match
[docs] def subproc_captured_stdout(*cmds, envs=None): """Runs a subprocess, capturing the output. Returns the stdout that was produced as a str or list based on ``$XONSH_SUBPROC_OUTPUT_FORMAT``. """ import xonsh.procs.specs return xonsh.procs.specs.run_subproc(cmds, captured="stdout", envs=envs)
[docs] def subproc_captured_inject(*cmds, envs=None): """Runs a subprocess, capturing the output. Returns a list of whitespace-separated strings of the stdout that was produced. The string is split using xonsh's lexer, rather than Python's str.split() or shlex.split(). """ import xonsh.procs.specs o = xonsh.procs.specs.run_subproc(cmds, captured="object", envs=envs) o.end() toks = [] for line in o: line = line.rstrip(os.linesep) toks.extend(XSH.execer.parser.lexer.split(line)) return toks
[docs] def subproc_captured_object(*cmds, envs=None): """ Runs a subprocess, capturing the output. Returns an instance of CommandPipeline representing the completed command. """ import xonsh.procs.specs return xonsh.procs.specs.run_subproc(cmds, captured="object", envs=envs)
[docs] def subproc_captured_hiddenobject(*cmds, envs=None): """Runs a subprocess, capturing the output. Returns an instance of HiddenCommandPipeline representing the completed command. """ import xonsh.procs.specs return xonsh.procs.specs.run_subproc(cmds, captured="hiddenobject", envs=envs)
[docs] def subproc_uncaptured(*cmds, envs=None): """Runs a subprocess, without capturing the output. Returns the stdout that was produced as a str. """ import xonsh.procs.specs return xonsh.procs.specs.run_subproc(cmds, captured=False, envs=envs)
[docs] def ensure_list_of_strs(x): """Ensures that x is a list of strings.""" if isinstance(x, str): rtn = [x] elif isinstance(x, cabc.Sequence): rtn = [i if isinstance(i, str) else str(i) for i in x] else: rtn = [str(x)] return rtn
[docs] def ensure_str_or_callable(x): """Ensures that x is single string or function.""" if isinstance(x, str) or callable(x): return x if isinstance(x, bytes): # ``os.fsdecode`` decodes using "surrogateescape" on linux and "strict" on windows. # This is used to decode bytes for interfacing with the os, notably for command line arguments. # See https://www.python.org/dev/peps/pep-0383/#specification return os.fsdecode(x) return str(x)
[docs] def list_of_strs_or_callables(x): """ Ensures that x is a list of strings or functions. This is called when using the ``@()`` operator to expand it's content. """ if isinstance(x, (str, bytes)) or callable(x): rtn = [ensure_str_or_callable(x)] elif isinstance(x, cabc.Iterable): rtn = list(map(ensure_str_or_callable, x)) else: rtn = [ensure_str_or_callable(x)] return rtn
[docs] def list_of_list_of_strs_outer_product(x): """Takes an outer product of a list of strings""" lolos = map(ensure_list_of_strs, x) rtn = [] for los in itertools.product(*lolos): s = "".join(los) if "*" in s: rtn.extend(XSH.glob(s)) else: rtn.append(XSH.expand_path(s)) return rtn
[docs] def eval_fstring_field(field): """Evaluates the argument in Xonsh context.""" res = XSH.execer.eval( field[0].strip(), glbs=globals(), locs=XSH.ctx, filename=field[1] ) return res
@lazyobject def MACRO_FLAG_KINDS(): return { "s": str, "str": str, "string": str, "a": AST, "ast": AST, "c": types.CodeType, "code": types.CodeType, "compile": types.CodeType, "v": eval, "eval": eval, "x": exec, "exec": exec, "t": type, "type": type, } def _convert_kind_flag(x): """Puts a kind flag (string) a canonical form.""" x = x.lower() kind = MACRO_FLAG_KINDS.get(x, None) if kind is None: raise TypeError(f"{x!r} not a recognized macro type.") return kind
[docs] def convert_macro_arg(raw_arg, kind, glbs, locs, *, name="<arg>", macroname="<macro>"): """Converts a string macro argument based on the requested kind. Parameters ---------- raw_arg : str The str representation of the macro argument. kind : object A flag or type representing how to convert the argument. glbs : Mapping The globals from the call site. locs : Mapping or None The locals from the call site. name : str, optional The macro argument name. macroname : str, optional The name of the macro itself. Returns ------- The converted argument. """ # munge kind and mode to start mode = None if isinstance(kind, cabc.Sequence) and not isinstance(kind, str): # have (kind, mode) tuple kind, mode = kind if isinstance(kind, str): kind = _convert_kind_flag(kind) if kind is str or kind is None: return raw_arg # short circuit since there is nothing else to do # select from kind and convert execer = XSH.execer filename = macroname + "(" + name + ")" if kind is AST: ctx = set(dir(builtins)) | set(glbs.keys()) if locs is not None: ctx |= set(locs.keys()) mode = mode or "eval" if mode != "eval" and not raw_arg.endswith("\n"): raw_arg += "\n" arg = execer.parse(raw_arg, ctx, mode=mode, filename=filename) elif kind is types.CodeType or kind is compile: # NOQA mode = mode or "eval" arg = execer.compile( raw_arg, mode=mode, glbs=glbs, locs=locs, filename=filename ) elif kind is eval: arg = execer.eval(raw_arg, glbs=glbs, locs=locs, filename=filename) elif kind is exec: mode = mode or "exec" if not raw_arg.endswith("\n"): raw_arg += "\n" arg = execer.exec(raw_arg, mode=mode, glbs=glbs, locs=locs, filename=filename) elif kind is type: arg = type(execer.eval(raw_arg, glbs=glbs, locs=locs, filename=filename)) else: msg = "kind={0!r} and mode={1!r} was not recognized for macro " "argument {2!r}" raise TypeError(msg.format(kind, mode, name)) return arg
[docs] @contextlib.contextmanager def in_macro_call(f, glbs, locs): """Attaches macro globals and locals temporarily to function as a context manager. Parameters ---------- f : callable object The function that is called as ``f(*args)``. glbs : Mapping The globals from the call site. locs : Mapping or None The locals from the call site. """ prev_glbs = getattr(f, "macro_globals", None) prev_locs = getattr(f, "macro_locals", None) f.macro_globals = glbs f.macro_locals = locs yield if prev_glbs is None: del f.macro_globals else: f.macro_globals = prev_glbs if prev_locs is None: del f.macro_locals else: f.macro_locals = prev_locs
[docs] def call_macro(f, raw_args, glbs, locs): """Calls a function as a macro, returning its result. Parameters ---------- f : callable object The function that is called as ``f(*args)``. raw_args : tuple of str The str representation of arguments of that were passed into the macro. These strings will be parsed, compiled, evaled, or left as a string depending on the annotations of f. glbs : Mapping The globals from the call site. locs : Mapping or None The locals from the call site. """ sig = inspect.signature(f) empty = inspect.Parameter.empty macroname = f.__name__ i = 0 args = [] for (key, param), raw_arg in zip(sig.parameters.items(), raw_args): i += 1 if raw_arg == "*": break kind = param.annotation if kind is empty or kind is None: kind = str arg = convert_macro_arg( raw_arg, kind, glbs, locs, name=key, macroname=macroname ) args.append(arg) reg_args, kwargs = _eval_regular_args(raw_args[i:], glbs, locs) args += reg_args with in_macro_call(f, glbs, locs): rtn = f(*args, **kwargs) return rtn
@lazyobject def KWARG_RE(): return re.compile(r"([A-Za-z_]\w*=|\*\*)") def _starts_as_arg(s): """Tests if a string starts as a non-kwarg string would.""" return KWARG_RE.match(s) is None def _eval_regular_args(raw_args, glbs, locs): if not raw_args: return [], {} arglist = list(itertools.takewhile(_starts_as_arg, raw_args)) kwarglist = raw_args[len(arglist) :] execer = XSH.execer if not arglist: args = arglist kwargstr = "dict({})".format(", ".join(kwarglist)) kwargs = execer.eval(kwargstr, glbs=glbs, locs=locs) elif not kwarglist: argstr = "({},)".format(", ".join(arglist)) args = execer.eval(argstr, glbs=glbs, locs=locs) kwargs = {} else: argstr = "({},)".format(", ".join(arglist)) kwargstr = "dict({})".format(", ".join(kwarglist)) both = f"({argstr}, {kwargstr})" args, kwargs = execer.eval(both, glbs=glbs, locs=locs) return args, kwargs
[docs] def enter_macro(obj, raw_block, glbs, locs): """Prepares to enter a context manager macro by attaching the contents of the macro block, globals, and locals to the object. These modifications are made in-place and the original object is returned. Parameters ---------- obj : context manager The object that is about to be entered via a with-statement. raw_block : str The str of the block that is the context body. This string will be parsed, compiled, evaled, or left as a string depending on the return annotation of obj.__enter__. glbs : Mapping The globals from the context site. locs : Mapping or None The locals from the context site. Returns ------- obj : context manager The same context manager but with the new macro information applied. """ # recurse down sequences if isinstance(obj, cabc.Sequence): for x in obj: enter_macro(x, raw_block, glbs, locs) return obj # convert block as needed kind = getattr(obj, "__xonsh_block__", str) macroname = getattr(obj, "__name__", "<context>") block = convert_macro_arg( raw_block, kind, glbs, locs, name="<with!>", macroname=macroname ) # attach attrs obj.macro_globals = glbs obj.macro_locals = locs obj.macro_block = block return obj
[docs] @contextlib.contextmanager def xonsh_builtins(execer=None): """A context manager for using the xonsh builtins only in a limited scope. Likely useful in testing. """ XSH.load(execer=execer) yield XSH.unload()
[docs] class InlineImporter: """Inline importer allows to import and use module attribute or function in one line.""" def __getattr__(self, name): if name.startswith("__"): return getattr(super(), name) return __import__(name)
[docs] class XonshSession: """All components defining a xonsh session.""" def __init__(self): """ Attributes ---------- exit: int or None Session attribute. In case of integer value it signals xonsh to exit with returning this value as exit code. """ self.execer = None self.ctx = {} self.builtins_loaded = False self.history = None self.shell = None self.env = None self.imp = InlineImporter() self.rc_files = None # AST-invoked functions self.help = helper self.superhelp = superhelper self.pathsearch = pathsearch self.globsearch = globsearch self.regexsearch = regexsearch self.glob = globpath self.expand_path = expand_path self.subproc_captured_stdout = subproc_captured_stdout self.subproc_captured_inject = subproc_captured_inject self.subproc_captured_object = subproc_captured_object self.subproc_captured_hiddenobject = subproc_captured_hiddenobject self.subproc_uncaptured = subproc_uncaptured self.call_macro = call_macro self.enter_macro = enter_macro self.path_literal = path_literal self.list_of_strs_or_callables = list_of_strs_or_callables self.list_of_list_of_strs_outer_product = list_of_list_of_strs_outer_product self.eval_fstring_field = eval_fstring_field # Session attributes self.exit = None self.stdout_uncaptured = None self.stderr_uncaptured = None self._py_exit = None self._py_quit = None self.commands_cache = None self.modules_cache = None self.all_jobs = None self._completers = None self.builtins = None self._initial_builtin_names = None self.last = None # Last executed CommandPipeline. @property def aliases(self): if self.commands_cache is None: return return self.commands_cache.aliases @property def completers(self): """Returns a list of all available completers. Init when first accessing the attribute""" if self._completers is None: from xonsh.completers.init import default_completers self._completers = default_completers(self.commands_cache) return self._completers def _disable_python_exit(self): # Disable Python interactive quit/exit if hasattr(builtins, "exit"): self._py_exit = builtins.exit del builtins.exit if hasattr(builtins, "quit"): self._py_quit = builtins.quit del builtins.quit def _restore_python_exit(self): if self._py_exit is not None: builtins.exit = self._py_exit if self._py_quit is not None: builtins.quit = self._py_quit
[docs] def load(self, execer=None, ctx=None, inherit_env=True, **kwargs): """Loads the session with default values. Parameters ---------- execer : Execer, optional Xonsh execution object, may be None to start ctx : Mapping, optional Context to start xonsh session with. inherit_env : bool If ``True``: inherit environment variables from ``os.environ``. If ``False``: use default values for environment variables and set ``$XONSH_ENV_INHERITED = False``. """ from xonsh.commands_cache import CommandsCache from xonsh.environ import Env, default_env if not hasattr(builtins, "__xonsh__"): builtins.__xonsh__ = self if ctx is not None: self.ctx = ctx if "env" in kwargs: self.env = kwargs.pop("env") elif inherit_env: self.env = Env(default_env()) else: self.env = Env({"XONSH_ENV_INHERITED": False}) self.exit = None self.stdout_uncaptured = None self.stderr_uncaptured = None self._disable_python_exit() self.execer = execer self.modules_cache = {} self.all_jobs = {} self.builtins = get_default_builtins(execer) self._initial_builtin_names = frozenset(vars(self.builtins)) aliases_given = kwargs.pop("aliases", None) for attr, value in kwargs.items(): if hasattr(self, attr): setattr(self, attr, value) self.commands_cache = ( kwargs.pop("commands_cache") if "commands_cache" in kwargs else CommandsCache(self.env, aliases_given) ) self.link_builtins() self.builtins_loaded = True def flush_on_exit(s=None, f=None): if self.history is not None: self.history.flush(at_exit=True) atexit.register(flush_on_exit) # Add one-shot handler for exit for sig in AT_EXIT_SIGNALS: resetting_signal_handle(sig, flush_on_exit)
[docs] def unload(self): if not hasattr(builtins, "__xonsh__"): self.builtins_loaded = False return if hasattr(self.env, "undo_replace_env"): self.env.undo_replace_env() self._restore_python_exit() if not self.builtins_loaded: return if self.history is not None: self.history.flush(at_exit=True) self.unlink_builtins() delattr(builtins, "__xonsh__") self.builtins_loaded = False self._completers = None
[docs] def get_default_builtins(execer=None): from xonsh.events import events return types.SimpleNamespace( XonshError=XonshError, XonshCalledProcessError=XonshCalledProcessError, evalx=None if execer is None else execer.eval, execx=None if execer is None else execer.exec, compilex=None if execer is None else execer.compile, events=events, print_color=print_color, printx=print_color, )
[docs] class DynamicAccessProxy: """Proxies access dynamically.""" def __init__(self, refname, objname): """ Parameters ---------- refname : str '.'-separated string that represents the new, reference name that the user will access. objname : str '.'-separated string that represents the name where the target object actually lives that refname points to. """ super().__setattr__("refname", refname) super().__setattr__("objname", objname) @property def obj(self): """Dynamically grabs object""" names = self.objname.split(".") obj = builtins for name in names: obj = getattr(obj, name) return obj def __getattr__(self, name): return getattr(self.obj, name) def __setattr__(self, name, value): return super().__setattr__(self.obj, name, value) def __delattr__(self, name): return delattr(self.obj, name) def __getitem__(self, item): return self.obj.__getitem__(item) def __setitem__(self, item, value): return self.obj.__setitem__(item, value) def __delitem__(self, item): del self.obj[item] def __call__(self, *args, **kwargs): return self.obj.__call__(*args, **kwargs) def __dir__(self): return self.obj.__dir__()
# singleton XSH = XonshSession()