Only load mpl style when using CLI

This avoids altering mpl settings in a script that imports stagpy.
`mplstyle` and `xkcd` options of `conf.plot` are now CLI only.  This
commit also avoids calling `load_mplstyle` twice when using the CLI.
The `load_mplstyle` function is no longer part of the public API.

Author: amorison

stagpy/__init__.py

@@ -75,28 +75,6 @@ def _check_config() -> None:
                 shutil.copy(str(stfile_local), str(stfile_conf))
 
 
-def load_mplstyle() -> None:
-    """Try to load conf.plot.mplstyle matplotlib style."""
-    import matplotlib.style as mpls
-    if conf.plot.mplstyle:
-        for style in conf.plot.mplstyle.split():
-            style_fname = style + ".mplstyle"
-            if not ISOLATED:
-                stfile = config.CONFIG_DIR / style_fname
-                if stfile.is_file():
-                    mpls.use(str(stfile))
-                    continue
-            # try packaged version
-            if imlr.is_resource(_styles, style_fname):
-                with imlr.path(_styles, style_fname) as stfile:
-                    mpls.use(str(stfile))
-                    continue
-            mpls.use(style)
-    if conf.plot.xkcd:
-        import matplotlib.pyplot as plt
-        plt.xkcd()
-
-
 if DEBUG:
     print('StagPy runs in DEBUG mode because the environment variable',
           'STAGPY_DEBUG is set to "True"', sep='\n', end='\n\n')
@@ -119,7 +97,5 @@ def load_mplstyle() -> None:
     _check_config()
 PARSING_OUT = conf.read_configs_()
 
-load_mplstyle()
-
 if not DEBUG:
     signal.signal(signal.SIGINT, _PREV_INT)

stagpy/args.py

@@ -3,14 +3,19 @@
 from __future__ import annotations
 from inspect import isfunction
 from types import MappingProxyType
+import importlib.resources as imlr
 import typing
 
 from loam.tools import set_conf_str, create_complete_files
 from loam.cli import Subcmd, CLIManager
+import matplotlib.pyplot as plt
+import matplotlib.style as mpls
 
 from . import __doc__ as doc_module
-from . import conf, PARSING_OUT, load_mplstyle
-from . import commands, field, rprof, time_series, refstate, plates
+from . import conf, PARSING_OUT, ISOLATED
+from . import (
+    commands, config, field, rprof, time_series, refstate, plates, _styles,
+)
 from ._helpers import baredoc
 from .config import CONFIG_DIR
 
@@ -30,6 +35,26 @@ def _bare_cmd() -> None:
     print('Run `stagpy -h` for usage')
 
 
+def _load_mplstyle() -> None:
+    """Try to load conf.plot.mplstyle matplotlib style."""
+    if conf.plot.mplstyle:
+        for style in conf.plot.mplstyle.split():
+            style_fname = style + ".mplstyle"
+            if not ISOLATED:
+                stfile = config.CONFIG_DIR / style_fname
+                if stfile.is_file():
+                    mpls.use(str(stfile))
+                    continue
+            # try packaged version
+            if imlr.is_resource(_styles, style_fname):
+                with imlr.path(_styles, style_fname) as stfile:
+                    mpls.use(str(stfile))
+                    continue
+            mpls.use(style)
+    if conf.plot.xkcd:
+        plt.xkcd()
+
+
 SUB_CMDS = MappingProxyType({
     'common_': Subcmd(doc_module, 'common', func=_bare_cmd),
     'field': _sub(field, 'core', 'plot', 'scaling'),
@@ -75,6 +100,6 @@ def parse_args(arglist: Optional[List[str]] = None) -> Callable[[], None]:
     if conf.common.config:
         commands.config_pp(climan.sections_list(sub_cmd))
 
-    load_mplstyle()
+    _load_mplstyle()
 
     return cmd_args.func

stagpy/config.py

@@ -56,8 +56,8 @@
                   False, 'arbitrary isoline value, comma separated'),
     mplstyle=Conf('stagpy-paper', True, None,
                   {'nargs': '?', 'const': '', 'type': str},
-                  True, 'matplotlib style'),
-    xkcd=Conf(False, False, None, {}, True, 'use the xkcd style'),
+                  False, 'matplotlib style'),
+    xkcd=command_flag(None, 'use the xkcd style'),
 )
 
 CONF_DEF['scaling'] = dict(