Add installation instruction file;

Order directories.

rivista/config.py

@@ -0,0 +1,116 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+"""
+Functions get_directory() were taken from project jarun/buku.
+By Arun Prakash Jana (jarun) and Dmitry Marakasov (AMDmi3).
+"""
+
+import os
+import sys
+try:
+    import tomllib
+except:
+    import tomli as tomllib
+
+class Settings:
+
+    def get_directory():
+        """
+        Determine the directory path where setting files be stored.
+    
+        * If $XDG_CONFIG_HOME is defined, use it;
+        * else if $HOME exists, use it;
+        * else if the platform is Windows, use %APPDATA%;
+        * else use the current directory.
+    
+        Returns
+        -------
+        str
+            Path to configuration directory.
+        """
+    #    config_home = xdg.BaseDirectory.xdg_config_home
+        config_home = os.environ.get('XDG_CONFIG_HOME')
+        if config_home is None:
+            if os.environ.get('HOME') is None:
+                if sys.platform == 'win32':
+                    config_home = os.environ.get('APPDATA')
+                    if config_home is None:
+                        return os.path.abspath('.')
+                else:
+                    return os.path.abspath('.')
+            else:
+                config_home = os.path.join(
+                    os.environ.get('HOME'), '.config'
+                    )
+        return os.path.join(config_home, 'rivista')
+
+    def get_setting(filename, section):
+        with open(filename, mode="rb") as settings:
+            result = tomllib.load(settings)[section]
+        return result
+
+
+class Data:
+
+    def get_directory():
+        """
+        Determine the directory path where data files be stored.
+    
+        * If $XDG_DATA_HOME is defined, use it;
+        * else if $HOME exists, use it;
+        * else if the platform is Windows, use %APPDATA%;
+        * else use the current directory.
+    
+        Returns
+        -------
+        str
+            Path to database file.
+        """
+    #    data_home = xdg.BaseDirectory.xdg_data_home
+        data_home = os.environ.get('XDG_DATA_HOME')
+        if data_home is None:
+            if os.environ.get('HOME') is None:
+                if sys.platform == 'win32':
+                    data_home = os.environ.get('APPDATA')
+                    if data_home is None:
+                        return os.path.abspath('.rivista/data')
+                else:
+                    return os.path.abspath('.rivista/data')
+            else:
+                data_home = os.path.join(
+                    os.environ.get('HOME'), '.local', 'share'
+                    )
+        return os.path.join(data_home, 'rivista')
+
+class Cache:
+
+    def get_directory():
+        """
+        Determine the directory path where cache files be stored.
+    
+        * If $XDG_CACHE_HOME is defined, use it;
+        * else if $HOME exists, use it;
+        * else if the platform is Windows, use %APPDATA%;
+        * else use the current directory.
+    
+        Returns
+        -------
+        str
+            Path to cache directory.
+        """
+    #    cache_home = xdg.BaseDirectory.xdg_cache_home
+        cache_home = os.environ.get('XDG_CACHE_HOME')
+        if cache_home is None:
+            if os.environ.get('HOME') is None:
+                if sys.platform == 'win32':
+                    cache_home = os.environ.get('APPDATA')
+                    if cache_home is None:
+                        return os.path.abspath('.rivista/cache')
+                else:
+                    return os.path.abspath('.rivista/cache')
+            else:
+                cache_home = os.path.join(
+                    os.environ.get('HOME'), '.cache'
+                    )
+        return os.path.join(cache_home, 'rivista')