"""
Helpers for tkinter
:githublink:`%|py|5`
"""
import os
import sys
import warnings
import ctypes
_first_execution = False
[docs]def fix_tkinter_issues_virtualenv(exc=True, fLOG=None):
"""
Fix an issue which happens in a virtual environment,
see `Fix Tcl inside a virtualenv on Windows <https://github.com/pypa/virtualenv/pull/627>`_
:param exc: raise an exception instead of a warning
:param fLOG: logging function
:return: list of environment variables
We try to deal with the following issue on Linux::
_tkinter.TclError: no display name and no $DISPLAY
On Linux, the solution is to run::
import matplotlib as mpl
mpl.use('Agg')
But it does not work if matplotlib was already imported.
It is recommended to delay its import
whenever it is possible.
:githublink:`%|py|34`
"""
global _first_execution
def location():
site = os.path.normpath(os.path.dirname(
os.path.join(os.path.abspath(ctypes.__file__))))
rev = os.path.join(site, "..", "..")
if sys.platform.startswith("win"):
site = os.path.join(rev, "tcl")
if not os.path.exists(site):
site2 = os.path.join(rev, "..", "tcl")
if os.path.exists(site2):
site = site2
else:
mes = ", ".join(os.listdir(rev))
raise FileNotFoundError(
"Unable to find: {0},\nsubfolders: {1}".format(site, mes))
else:
site = os.path.join(rev, "..", "tcl")
if not os.path.exists(site):
mes = ", ".join(os.listdir(os.path.join(rev, "..")))
raise FileNotFoundError(
"unable to find: {0},\nsubfolders: {1}".format(site, mes))
return os.path.normpath(site)
def look_for(where, prefix):
lst = sorted(os.listdir(where), reverse=True)
lp = len(prefix)
for _ in lst:
if _.startswith(prefix) and "0" <= _[lp] <= "9" and ".lib" not in _:
return os.path.join(where, _)
raise FileNotFoundError("Unable to find any folder starting with {0} in {1}\nLIST:\n{2}".format(
prefix, where, ", ".join(lst)))
if sys.platform.startswith("win"):
if "matplotlib" in sys.modules:
if _first_execution:
warnings.warn(
"Cannot fix matplotlib display because it was already imported.", UserWarning)
if exc:
raise Exception(
"Cannot fix matplotlib display because it was already imported.")
if "TCL_LIBRARY" not in os.environ:
loc = location()
p = look_for(loc, "tcl")
if fLOG:
fLOG("[fix_tkinter_issues_virtualenv] Change {0}: '{1}' --> '{2}'".format("TCL_LIBRARY",
os.environ.get("TCL_LIBRARY", None), p))
os.environ["TCL_LIBRARY"] = p
if fLOG:
fLOG("[fix_tkinter_issues_virtualenv] TCL_LIBRARY='{0}'".format(
os.environ["TCL_LIBRARY"]))
if "TK_LIBRARY" not in os.environ:
loc = location()
p = look_for(loc, "tk")
if fLOG:
fLOG("[fix_tkinter_issues_virtualenv] Change {0}: '{1}' --> '{2}'".format("TK_LIBRARY",
os.environ.get("TK_LIBRARY", None), p))
os.environ["TK_LIBRARY"] = p
if fLOG:
fLOG("[fix_tkinter_issues_virtualenv] TK_LIBRARY='{0}'".format(
os.environ["TK_LIBRARY"]))
if "TIX_LIBRARY" not in os.environ:
loc = location()
p = look_for(loc, "tix")
if fLOG:
fLOG("[fix_tkinter_issues_virtualenv] Change {0}: '{1}' --> '{2}'".format("TIX_LIBRARY",
os.environ.get("TIX_LIBRARY", None), p))
os.environ["TIX_LIBRARY"] = p
if fLOG:
fLOG("[fix_tkinter_issues_virtualenv] TIX_LIBRARY='{0}'".format(
os.environ["TIX_LIBRARY"]))
if "DISPLAY" not in os.environ:
p = ":0"
if fLOG:
fLOG("Change {0}: '{1}' --> '{2}'".format("DISPLAY",
os.environ.get("DISPLAY", None), p))
os.environ["DISPLAY"] = p
else:
# if "DISPLAY" not in os.environ:
# os.environ["DISPLAY"] = ':10.0'
if fLOG:
fLOG("[fix_tkinter_issues_virtualenv] Call mpl.use('Agg')")
if "matplotlib" in sys.modules:
if _first_execution:
warnings.warn(
"Cannot fix matplotlib display because it was already imported.", UserWarning)
if exc:
raise Exception(
"Cannot fix matplotlib display because it was already imported.")
import matplotlib as mpl
mpl.use('Agg')
else:
import matplotlib as mpl
mpl.use('Agg')
_first_execution = False
return os.environ.get("TCL_LIBRARY", None), os.environ.get("TK_LIBRARY", None), \
os.environ.get("TIX_LIBRARY", None), os.environ.get("DISPLAY", None)
