fix: don't allow empty file and check folder's existance

.gitignore

@@ -1,2 +1,6 @@
 /test.py
-/piecharttest.py
+/piecharttest.py
+*.idea
+*.vscode
+*output
+*.json

Converter.py

@@ -34,6 +34,9 @@
 
 with open(fileName) as json_file:
     data = json.load(json_file)
+    if data=={}:
+        print("data is empty")
+        exit(-1)
 
 
 #0
@@ -67,6 +70,8 @@ def BarGraph():
     what = str(input("Do you want to save this? (y/n): ")).lower()
     if what == "y":
         name = str(input("Enter the name for the file: "))
+        if not os.path.exists("./output/"):
+            os.mkdir("./output/")
         plt.savefig("./output/" + name)
         print("File saved!")
     plt.show()

README.md

@@ -2,6 +2,6 @@
 
 ## Steps
 1. Export your WakaTime coding activity as json [here](https://wakatime.com/settings/account)
-2. Replace the data.json file with the new json file
+2. Put your json file in `/input` folder, one file per run.
 3. Run Converter.py
 4. Choose your option