from pandas import json_normalize normalized = json_normalize(payload) rows.append(normalized.iloc[0].to_dict()) What About Invalid or Expired Signatures? A pure converter doesn’t need to verify the signature – it just decodes the payload. However, you may want to add a signature_valid column using a cryptographic library (e.g., cryptography or jwt with verification disabled first, then verified separately).
To flatten these into CSV columns (e.g., user.id , permissions.0 ), you can use pandas.json_normalize() instead of the direct DataFrame constructor.
def jws_to_csv(input_file, output_file, fields_of_interest=None): """ Convert a file of JWS tokens (one per line) to CSV. fields_of_interest: list of claim names to extract (e.g., ['sub', 'exp', 'role']) """ tokens = Path(input_file).read_text().splitlines() rows = []
for token in tokens: if not token.strip(): continue payload = decode_jws_payload(token) # If no fields specified, take all top-level keys if fields_of_interest is None: rows.append(payload) else: filtered = field: payload.get(field, None) for field in fields_of_interest rows.append(filtered) jws to csv converter
If you work with JWT (JSON Web Tokens) or JWS (JSON Web Signatures) in logging, analytics, or batch processing, you’ve likely run into the same headache: how do you analyze hundreds or thousands of these tokens in a human-readable way?
pip install PyJWT pandas import base64 import json import csv import sys import pandas as pd from pathlib import Path def decode_jws_payload(jws_token): """Decode the payload (second part) of a compact JWS.""" try: parts = jws_token.split('.') if len(parts) != 3: raise ValueError("Invalid compact JWS: expected 3 parts") # Decode base64url (add padding if needed) payload_b64 = parts[1] # Add padding for base64 decoding padding = '=' * (4 - (len(payload_b64) % 4)) payload_bytes = base64.urlsafe_b64decode(payload_b64 + padding) return json.loads(payload_bytes) except Exception as e: return "error": str(e), "raw_token": jws_token[:50]
df = pd.DataFrame(rows) df.to_csv(output_file, index=False) print(f"✅ Converted len(rows) tokens to output_file") if == " main ": # Example usage jws_to_csv("tokens.txt", "output.csv", fields_of_interest=["sub", "exp", "tenant_id"]) Step 3: Handling nested claims Sometimes your JWS payload contains nested objects: To flatten these into CSV columns (e
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjMiLCJyb2xlIjoidXNlciIsImV4cCI6MTczNTY4OTAwMH0.signature1 eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiI0NTYiLCJyb2xlIjoiYWRtaW4iLCJleHAiOjE3MzU2ODkwMDB9.signature2 python jws_to_csv.py tokens.txt output.csv --fields sub,role
Once you have the CSV, the world opens up – pivot tables, duplicate detection, expiration audits, and even machine learning on claim patterns.
Do not trust the claims from an unverified JWS in a security context. For analysis, it’s fine. For access control, always verify the signature. Real-World Example Input ( tokens.txt ): pip install PyJWT pandas import base64 import json
Replace the row-building section with:
Extend the script to handle JWE (encrypted tokens) or add signature validation columns. Happy data wrangling. Have you built a similar converter for a different token format? Let me know in the comments.