PayU India Python Integration

PayU India payment gateway. PACKAGE NAME CONFUSION: 'payu' on PyPI (1.2.1) is an unrelated HPC workflow tool — NOT PayU payments. Official PayU India Python SDK is 'payu_websdk' (from payu-india/web-sdk-python on GitHub, not on PyPI). 'payu-sdk' (1.2.0 on PyPI) is unofficial/community. Most Python integrations use manual hash generation without any SDK. Core requirement: SHA512 hash must be generated server-side for every transaction. Amount as string in rupees. Test environment: test.payu.in, Live: secure.payu.in.