v1.8.0 (#105)

## Change log
  
- Youtube support added
- Custom filenames feature added
- Custom folder structure feature added
- Unsaving downloaded posts option added
- Remove duplicate posts on different subreddits option added
- Skipping given domains option added
- Keeping track of already downloaded posts on a separate file option added (See --dowloaded-posts in README)
- No audio on v.redd.it videos bug fixed (see README for details about ffmpeg)
- --default-directory option is added
- --default-options is added
- --use-local-config option is added
- Bug fixes

src/jsonHelper.py

@@ -0,0 +1,58 @@
+import json
+from os import path, remove
+
+from src.errors import InvalidJSONFile
+
+class JsonFile:
+    """ Write and read JSON files
+
+    Use add(self,toBeAdded) to add to files
+
+    Use delete(self,*deletedKeys) to delete keys
+    """
+    
+    FILEDIR = ""
+
+    def __init__(self,FILEDIR):
+        self.FILEDIR = FILEDIR
+        if not path.exists(self.FILEDIR):
+            self.__writeToFile({},create=True)
+
+    def read(self):
+        try:
+            with open(self.FILEDIR, 'r') as f:
+                return json.load(f)
+        except json.decoder.JSONDecodeError:
+            raise InvalidJSONFile(f"{self.FILEDIR} cannot be read")
+
+    def add(self,toBeAdded,sub=None):
+        """Takes a dictionary and merges it with json file.
+        It uses new key's value if a key already exists.
+        Returns the new content as a dictionary.
+        """
+
+        data = self.read()
+        if sub: data[sub] = {**data[sub], **toBeAdded}
+        else: data = {**data, **toBeAdded}
+        self.__writeToFile(data)
+        return self.read()
+
+    def delete(self,*deleteKeys):
+        """Delete given keys from JSON file.
+        Returns the new content as a dictionary.
+        """
+
+        data = self.read()
+        for deleteKey in deleteKeys:
+            if deleteKey in data:
+                del data[deleteKey]
+                found = True
+        if not found:
+            return False
+        self.__writeToFile(data)
+
+    def __writeToFile(self,content,create=False):
+        if not create:
+            remove(self.FILEDIR)
+        with open(self.FILEDIR, 'w') as f:
+            json.dump(content, f, indent=4)