Add filter for languages with full ll_CC description

Author: columbarius

tldr.py

@@ -30,10 +30,19 @@
     'https://tldr-pages.github.io/assets/tldr.zip'
 )
 
-DEFAULT_LANG = os.environ.get(
-    'LANG',
-    'C'
-).split('_')[0]
+def filter_languages(lang):
+    if lang in ['pt_PT', 'pt_BR', 'zh_TW']:
+        return lang
+    elif lang == "pt":
+        return "pt_PT"
+    else:
+        return lang.split('_')[0]
+
+DEFAULT_LANG = filter_languages(
+    os.environ.get(
+        'LANG',
+        'C'
+    ).split('.')[0])
 
 if DEFAULT_LANG == 'C' or DEFAULT_LANG == 'POSIX':
     DEFAULT_LANG = None
@@ -162,9 +171,11 @@ def get_platform_list():
 def get_language_list():
     languages = os.environ.get('LANGUAGE', '').split(':')
     languages = list(map(
-        lambda x: x.split('_')[0],
-        filter(lambda x: not (x == 'C' or x == 'POSIX' or x == ''), languages)
-    ))
+        filter_languages,
+        map(
+            lambda x: x.split('.')[0],
+            filter(lambda x: not (x == 'C' or x == 'POSIX' or x == ''), languages)
+    )))
     if DEFAULT_LANG is not None:
         if DEFAULT_LANG not in languages:
             languages.append(DEFAULT_LANG)