Automatic Chinese fonts plotting (#4951)

* Automatic Chinese fonts plotting

* Default PIL=False

utils/general.py

@@ -161,10 +161,9 @@ def is_pip():
     return 'site-packages' in Path(__file__).resolve().parts
 
 
-def is_ascii(s=''):
-    # Is string composed of all ASCII (no UTF) characters?
-    s = str(s)  # convert list, tuple, None, etc. to str
-    return len(s.encode().decode('ascii', 'ignore')) == len(s)
+def is_chinese(s='人工智能'):
+    # Is string composed of any Chinese characters?
+    return re.search('[\u4e00-\u9fff]', s)
 
 
 def emojis(str=''):