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python-basics/write-better-funcs/tip4.py at main · Brave-Python/python-basics · GitHub

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# example fn. for processing transaction

def process_payment(transaction_id: int, amount: float, currency: str, description: str = None):

print(f"Processing transaction {transaction_id}...")

print(f"Amount: {amount} {currency}")

if description:

print(f"Description: {description}")

# Usage

process_payment(1234, 100.0, 'USD', 'Payment for services')

# enforce keyword-only arguments to minimize errors

# make the optional `description` arg keyword-only

def process_payment(transaction_id: int, amount: float, currency: str, *, description: str = None):

print(f"Processing transaction {transaction_id}:")

print(f"Amount: {amount} {currency}")

if description:

print(f"Description: {description}")

# Usage

process_payment(1234, 100.0, 'USD', description='Payment for services')

process_payment(5678, 150.0, 'EUR', 'Invoice payment') # throws error as we try to pass in more positional args than allowed!