scrapy/scrapy/cmdline.py

236 lines
7.3 KiB
Python

from __future__ import annotations
import argparse
import cProfile
import inspect
import os
import sys
from importlib.metadata import entry_points
from typing import TYPE_CHECKING
import scrapy
from scrapy.commands import BaseRunSpiderCommand, ScrapyCommand, ScrapyHelpFormatter
from scrapy.crawler import CrawlerProcess
from scrapy.exceptions import UsageError
from scrapy.utils.misc import walk_modules
from scrapy.utils.project import get_project_settings, inside_project
from scrapy.utils.python import garbage_collect
if TYPE_CHECKING:
from collections.abc import Callable, Iterable
# typing.ParamSpec requires Python 3.10
from typing_extensions import ParamSpec
from scrapy.settings import BaseSettings, Settings
_P = ParamSpec("_P")
class ScrapyArgumentParser(argparse.ArgumentParser):
def _parse_optional(
self, arg_string: str
) -> tuple[argparse.Action | None, str, str | None] | None:
# if starts with -: it means that is a parameter not a argument
if arg_string[:2] == "-:":
return None
return super()._parse_optional(arg_string)
def _iter_command_classes(module_name: str) -> Iterable[type[ScrapyCommand]]:
# TODO: add `name` attribute to commands and merge this function with
# scrapy.utils.spider.iter_spider_classes
for module in walk_modules(module_name):
for obj in vars(module).values():
if (
inspect.isclass(obj)
and issubclass(obj, ScrapyCommand)
and obj.__module__ == module.__name__
and obj not in (ScrapyCommand, BaseRunSpiderCommand)
):
yield obj
def _get_commands_from_module(module: str, inproject: bool) -> dict[str, ScrapyCommand]:
d: dict[str, ScrapyCommand] = {}
for cmd in _iter_command_classes(module):
if inproject or not cmd.requires_project:
cmdname = cmd.__module__.split(".")[-1]
d[cmdname] = cmd()
return d
def _get_commands_from_entry_points(
inproject: bool, group: str = "scrapy.commands"
) -> dict[str, ScrapyCommand]:
cmds: dict[str, ScrapyCommand] = {}
if sys.version_info >= (3, 10):
eps = entry_points(group=group)
else:
eps = entry_points().get(group, ())
for entry_point in eps:
obj = entry_point.load()
if inspect.isclass(obj):
cmds[entry_point.name] = obj()
else:
raise ValueError(f"Invalid entry point {entry_point.name}")
return cmds
def _get_commands_dict(
settings: BaseSettings, inproject: bool
) -> dict[str, ScrapyCommand]:
cmds = _get_commands_from_module("scrapy.commands", inproject)
cmds.update(_get_commands_from_entry_points(inproject))
cmds_module = settings["COMMANDS_MODULE"]
if cmds_module:
cmds.update(_get_commands_from_module(cmds_module, inproject))
return cmds
def _get_project_only_cmds(settings: BaseSettings) -> set[str]:
return set(_get_commands_dict(settings, inproject=True)) - set(
_get_commands_dict(settings, inproject=False)
)
def _pop_command_name(argv: list[str]) -> str | None:
for i in range(1, len(argv)):
if not argv[i].startswith("-"):
return argv.pop(i)
return None
def _print_header(settings: BaseSettings, inproject: bool) -> None:
version = scrapy.__version__
if inproject:
print(f"Scrapy {version} - active project: {settings['BOT_NAME']}\n")
else:
print(f"Scrapy {version} - no active project\n")
def _print_commands(settings: BaseSettings, inproject: bool) -> None:
_print_header(settings, inproject)
print("Usage:")
print(" scrapy <command> [options] [args]\n")
print("Available commands:")
cmds = _get_commands_dict(settings, inproject)
for cmdname, cmdclass in sorted(cmds.items()):
print(f" {cmdname:<13} {cmdclass.short_desc()}")
if not inproject:
print()
print(" [ more ] More commands available when run from project directory")
print()
print('Use "scrapy <command> -h" to see more info about a command')
def _print_unknown_command_msg(
settings: BaseSettings, cmdname: str, inproject: bool
) -> None:
proj_only_cmds = _get_project_only_cmds(settings)
if cmdname in proj_only_cmds and not inproject:
cmd_list = ", ".join(sorted(proj_only_cmds))
print(
f"The {cmdname} command is not available from this location.\n"
f"These commands are only available from within a project: {cmd_list}.\n"
)
else:
print(f"Unknown command: {cmdname}\n")
def _print_unknown_command(
settings: BaseSettings, cmdname: str, inproject: bool
) -> None:
_print_header(settings, inproject)
_print_unknown_command_msg(settings, cmdname, inproject)
print('Use "scrapy" to see available commands')
def _run_print_help(
parser: argparse.ArgumentParser,
func: Callable[_P, None],
*a: _P.args,
**kw: _P.kwargs,
) -> None:
try:
func(*a, **kw)
except UsageError as e:
if str(e):
parser.error(str(e))
if e.print_help:
parser.print_help()
sys.exit(2)
def execute(argv: list[str] | None = None, settings: Settings | None = None) -> None:
if argv is None:
argv = sys.argv
if settings is None:
settings = get_project_settings()
# set EDITOR from environment if available
try:
editor = os.environ["EDITOR"]
except KeyError:
pass
else:
settings["EDITOR"] = editor
inproject = inside_project()
cmds = _get_commands_dict(settings, inproject)
cmdname = _pop_command_name(argv)
if not cmdname:
_print_commands(settings, inproject)
sys.exit(0)
elif cmdname not in cmds:
_print_unknown_command(settings, cmdname, inproject)
sys.exit(2)
cmd = cmds[cmdname]
parser = ScrapyArgumentParser(
formatter_class=ScrapyHelpFormatter,
usage=f"scrapy {cmdname} {cmd.syntax()}",
conflict_handler="resolve",
description=cmd.long_desc(),
)
settings.setdict(cmd.default_settings, priority="command")
cmd.settings = settings
cmd.add_options(parser)
opts, args = parser.parse_known_args(args=argv[1:])
_run_print_help(parser, cmd.process_options, args, opts)
cmd.crawler_process = CrawlerProcess(settings)
_run_print_help(parser, _run_command, cmd, args, opts)
sys.exit(cmd.exitcode)
def _run_command(cmd: ScrapyCommand, args: list[str], opts: argparse.Namespace) -> None:
if opts.profile:
_run_command_profiled(cmd, args, opts)
else:
cmd.run(args, opts)
def _run_command_profiled(
cmd: ScrapyCommand, args: list[str], opts: argparse.Namespace
) -> None:
if opts.profile:
sys.stderr.write(f"scrapy: writing cProfile stats to {opts.profile!r}\n")
loc = locals()
p = cProfile.Profile()
p.runctx("cmd.run(args, opts)", globals(), loc)
if opts.profile:
p.dump_stats(opts.profile)
if __name__ == "__main__":
try:
execute()
finally:
# Twisted prints errors in DebugInfo.__del__, but PyPy does not run gc.collect() on exit:
# http://doc.pypy.org/en/latest/cpython_differences.html
# ?highlight=gc.collect#differences-related-to-garbage-collection-strategies
garbage_collect()