"""Finesse environment information."""
import sys
try:
from IPython.core.ultratb import AutoFormattedTB
except ImportError:
AutoFormattedTB = None
from .datastore import invalidate, init_singleton
# Platform detection.
IS_WINDOWS = sys.platform.startswith("win")
[docs]def traceback_handler_instance():
return init_singleton(_TracebackHandler)
[docs]def reset_traceback_handler():
invalidate(_TracebackHandler)
[docs]def is_interactive():
"""Check if Finesse is being run from an interactive environment.
Returns
-------
bool
`True` if a Jupyter notebook, Qt console or IPython shell is in use, `False`
otherwise.
"""
try:
shell = get_ipython().__class__.__name__
if shell == "ZMQInteractiveShell":
return True # Jupyter notebook or qtconsole
elif shell == "TerminalInteractiveShell":
return True # Terminal running IPython
else:
return False # Other type (?)
except NameError:
return False # Probably standard Python interpreter
[docs]def show_tracebacks(show_tb=None):
"""Get or set whether to show tracebacks in Jupyter/IPython in full form or just as
a single error message.
Parameters
----------
show_tb : bool, optional
Set whether to show tracebacks; defaults to None, which doesn't change the
current setting.
Returns
-------
bool
The current setting value (if `show_tb` was not set) or the previous setting
value (if `show_tb` was set).
"""
tb = traceback_handler_instance()
previous = tb.show_tb
if show_tb is not None:
tb.show_tb = show_tb
return previous
[docs]def tb():
"""Show the last traceback in full."""
tb = traceback_handler_instance()
tb.show_last()
[docs]def has_pygraphviz():
"""Determine if pygraphviz and graphviz are available on the current path.
Returns
-------
bool
`True` if pygraphviz and graphviz are available, `False` otherwise.
Notes
-----
This returns `False` if either pygraphviz or graphviz is not installed or correctly
configured. If pygraphviz is installed but graphviz is not installed or could not be
found, an import error complaining about something like "libagraph.so.1" is emitted
(see the `pygraphviz FAQ
<https://pygraphviz.github.io/documentation/stable/reference/faq.html>`_).
"""
try:
import pygraphviz # noqa: F401
except ImportError:
return False
return True
class _TracebackHandler:
"""Handler for user errors during parse and build.
This detects the environment within which the user is running Finesse - either a
normal Python terminal or script or within IPython or JupyterLab. Depending on the
environment, either complete tracebacks are shown or else only the error message.
The behaviour of this handler can be configured globally using
:func:`.show_tracebacks`.
Do not instantiate this class directly; use :func:`traceback_handler_instance`.
"""
def __init__(self):
self.show_tb = True
self.etype = None
self.evalue = None
self.tb = None
self.stb = None
self.text = None
self.a = None
if AutoFormattedTB is not None:
self.a = AutoFormattedTB(
mode="Context", color_scheme="Neutral", tb_offset=1
)
def store_tb(self):
import traceback
self.etype, self.evalue, self.tb = sys.exc_info()
if AutoFormattedTB is not None:
self.stb = self.a.structured_traceback(
self.etype, self.evalue, self.tb, tb_offset=1
)
self.text = self.a.stb2text(self.stb)
else:
self.text = traceback.format_exc()
def get_stb(self):
if self.show_tb:
return self.stb
else:
return self.stb[-1:]
def get_text(self):
return self.text
def show_last(self):
print(self.text)