Source code for bokeh.util.dependencies
''' Utilities for checking dependencies
'''
from importlib import import_module
import logging
import shutil
from subprocess import Popen, PIPE
from packaging.version import Version as V
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(version='2.1'):
''' Detect if PhantomJS is avaiable in PATH, at a minimum version.
Args:
version (str, optional) :
Required minimum version for PhantomJS (mostly for testing)
Returns:
str, path to PhantomJS
'''
if settings.phantomjs_path() is not None:
phantomjs_path = settings.phantomjs_path()
else:
if hasattr(shutil, "which"):
phantomjs_path = shutil.which("phantomjs") or "phantomjs"
else:
# Python 2 relies on Environment variable in PATH - attempt to use as follows
phantomjs_path = "phantomjs"
try:
proc = Popen([phantomjs_path, "--version"], stdout=PIPE, stderr=PIPE)
proc.wait()
out = proc.communicate()
if len(out[1]) > 0:
raise RuntimeError('Error encountered in PhantomJS detection: %r' % out[1].decode('utf8'))
required = V(version)
installed = V(out[0].decode('utf8'))
if installed < required:
raise RuntimeError('PhantomJS version to old. Version>=%s required, installed: %s' % (required, installed))
except OSError:
raise RuntimeError('PhantomJS is not present in PATH or BOKEH_PHANTOMJS_PATH. Try "conda install phantomjs" or \
"npm install -g phantomjs-prebuilt"')
return phantomjs_path