如果值存在而没有 if else

Question

This is my django model.

class AccountTransactions(models.Model):
  amount = models.DecimalField(max_digits=13, decimal_places=4, blank=True, null=True)

  @property
  def transaction_check(self):
      #what i want to do
      #If amount>0 :
           credit = amount
           debit = 0
      else;
           debit = amount
           credit = 0
      return credit, debit

How to write this if else in one line.

Answer 1

There is no ternary operator in Python, you can use a few methods. You can also use more simpler method:

@property
def transaction_check(self):
    return ((amount, 0), (0, amount))[0 < amount]

Maybe you can use different way to use map:

@property
def transaction_check(self):
    return {True: (amount, 0), False: (0, amount)}[0 < amount]

Also you can use lambda expression for the result:

@property
def transaction_check(self):
    return ((lambda: (amount, 0), lambda: (0, amount))[0 < amount]())

Billions different methods can be apply.

Answer 2

You can use a conditional expression with tuple assignment:

credit, debit = (amount, 0) if amount > 0 else (0, amount)

Answer 3

An alternative syntax to @Barmar's answer with no (visible) if/else:

class AccountTransactions(models.Model):
    amount = models.DecimalField(max_digits=13, decimal_places=4, blank=True, null=True)

    @property
    def transaction_check(self):
          return max(0, amount), min(amount, 0)