Recognize DARTS_CONFIGURE_MATPLOTLIB=0 (#924)

* recognize DARTS_CONFIGURE_MATPLOTLIB=0

* By default, darts still applies matplotlib configurations
* If the environment variable DARTS_CONFIGURE_MATPLOTLIB=0 is set, then
darts.u8plots_mplstyle is still defined but not applied

* add entry to change log

Author: zgana

CHANGELOG.md

@@ -5,6 +5,11 @@ Darts is still in an early development phase and we cannot always guarantee back
 
 ## [Unreleased](https://github.com/unit8co/darts/tree/master)
 [Full Changelog](https://github.com/unit8co/darts/compare/0.19.0...master)
+### For users of the library:
+
+**Improved**
+- Option to avoid global matplotlib configuration changes.
+  [#924](https://github.com/unit8co/darts/pull/924) by [Mike Richman](https://github.com/zgana).
 
 ## [0.19.0](https://github.com/unit8co/darts/tree/0.19.0) (2022-04-13)
 ### For users of the library:

darts/__init__.py

@@ -3,6 +3,8 @@
 -----
 """
 
+import os
+
 import matplotlib as mpl
 from matplotlib import cycler
 
@@ -37,4 +39,5 @@
 }
 
 
-mpl.rcParams.update(u8plots_mplstyle)
+if os.getenv("DARTS_CONFIGURE_MATPLOTLIB", "1") != "0":
+    mpl.rcParams.update(u8plots_mplstyle)