class __TransactionSet:
def __init__(self):
"""Initialize transaction store."""
self.store = OrderedSet()
def add(self, transaction):
self.store.add(transaction)
def add_multiple(self, transaction_list):
"""Add multiple transactions to the set.
Since the transactions are re-added to the set (they were in it once),
we add them at the front of the existing set.
"""
transaction_list = OrderedSet(transaction_list)
self.store = transaction_list.union(self.store)
def contains(self, transaction):
return self.store.__contains__(transaction)
def pop(self):
"""Remove and return a transaction from the set."""
try:
return self.store.pop(0)
# Catch KeyError if set is empty
except KeyError:
return None
def discard(self, transaction):
"""Remove the transaction if it was present in the set."""
self.store.discard(transaction)
def discard_multiple(self, transaction_list):
"""Remove multiple transactions from the set."""
[self.discard(tx) for tx in transaction_list]
def clear(self):
"""Remove all transactions from the set."""
self.store.clear()
def __len__(self):
return len(self.store)
def __iter__(self):
yield from self.store
def __repr__(self):
return self.store.__repr__()
