The Python code uses pyperclip module to get user data from clipboard.

CopyData.py

import pyperclip,sys,json
from os import path

"""
To install pyperclip use the following command:
pip install pyperclip
The code takes description from runtime variables
using sys module and paste the clipboard information
into a json file as key value pairs.
key=description, value=data in clipboard.
"""

if len(sys.argv)<2:
    print ("Usage: python copyData.py [description]")
    sys.exit()

descr=sys.argv[1]

filePath="/files/copyData.json"
fileExists=path.isfile(filePath)

# Empty dictionary.
clipboarddata={}

outfile=None
""" 
If file exists 
read JSON data,
convert JSON data into dictionary,
add new key value pair, convert
dictionary back to JSON data and
write to file.
Else
write to file.
"""
if fileExists:
    outfile=open(filePath,'r+')
    data=outfile.read()
    clipboarddata=json.loads(data)
    outfile.close()

outfile=open(filePath,'w+')
clipboarddata[descr]=pyperclip.paste()
outfile.write(json.dumps(clipboarddata))
outfile.close()