Source code for bokeh.util.dependencies

''' Utilities for checking dependencies

'''
from importlib import import_module
import logging
from subprocess import Popen, PIPE

from ..settings import settings

logger = logging.getLogger(__name__)


[docs]def import_optional(mod_name): ''' Attempt to import an optional dependency. Silently returns None if the requested module is not available. Args: mod_name (str) : name of the optional module to try to import Returns: imported module or None, if import fails ''' try: return import_module(mod_name) except ImportError: pass except Exception: msg = "Failed to import optional module `{}`".format(mod_name) logger.exception(msg)
[docs]def import_required(mod_name, error_msg): ''' Attempt to import a required dependency. Raises a RuntimeError if the requested module is not available. Args: mod_name (str) : name of the required module to try to import error_msg (str) : error message to raise when the module is missing Returns: imported module Raises: RuntimeError ''' try: return import_module(mod_name) except ImportError: raise RuntimeError(error_msg)
[docs]def detect_phantomjs(): '''Detect if PhantomJS is avaiable in PATH.''' if settings.phantomjs_path() is not None: phantomjs_path = settings.phantomjs_path() else: phantomjs_path = "phantomjs" try: proc = Popen([phantomjs_path, "--version"], stdout=PIPE, stderr=PIPE) proc.wait() except OSError: raise RuntimeError('PhantomJS is not present in PATH. Try "conda install phantomjs" or \ "npm install -g phantomjs-prebuilt"') else: return phantomjs_path