CounterToken
CounterToken is the most ambiguous of the tokens presented by this library. Do not use it if you are not sure that you understand how it works correctly. However, it can be very useful in situations where you want to limit the number of attempts to perform an operation.
CounterToken is initialized with an integer greater than zero. At each calculation of the answer to the question whether it is canceled, this number is reduced by one. When this number becomes zero, the token is considered canceled:
from cantok import CounterToken
token = CounterToken(5)
counter = 0
while token:
counter += 1
print(counter) # 5
The counter inside the CounterToken is reduced under one of three conditions:
- Access to the
cancelledattribute. - Calling the
is_cancelled()method. - Calling the
keep_on()method.
If you use CounterToken inside other tokens, the wrapping token can specify the status of the CounterToken. For security reasons, this operation does not decrease the counter. However, if for some reason you need it to decrease, pass direct - False as an argument:
from cantok import SimpleToken, CounterToken
first_counter_token = CounterToken(1, direct=False)
second_counter_token = CounterToken(1, direct=True)
print(SimpleToken(first_counter_token, second_counter_token).cancelled) # False
print(first_counter_token.cancelled) # True
print(second_counter_token.cancelled) # False
Like all other tokens, CounterToken can accept other tokens as parameters during initialization: