How do I return a value from a library I create?

Based on the provided code and the information from the extracts, it seems that 'Tom' is trying to separate the indicator logic from the main algorithm. However, the code provided does not show any usage of an external library for indicators.

In QuantConnect, you can create custom indicator classes and use them in your algorithm. The custom indicator class should inherit from the IndicatorBase<T> class, where T is the type of data the indicator uses (for example, IndicatorBase<TradeBar> for indicators that use trade bar data).

In the ComputeNextValue method of your custom indicator class, you can implement the logic for calculating the indicator value based on the new data input. The Current property of the indicator will hold the latest computed value.

Here is a simplified example of how you can structure a custom indicator:

class MyCustomIndicator(IndicatorBase<TradeBar>):
    def __init__(self):
        self.Current = 0

    def ComputeNextValue(self, data):
        # Implement your indicator logic here
        # For example, let's say the indicator value is the close price squared
        self.Current = data.Close ** 2

Then, in your main algorithm, you can create an instance of your custom indicator and update it with new data in the OnData method:

class MyAlgorithm(QCAlgorithm):
    def Initialize(self):
        self.my_indicator = MyCustomIndicator()

    def OnData(self, data):
        self.my_indicator.Update(data["SPY"])
        self.Debug(f"Current indicator value: {self.my_indicator.Current}")

Please note that this is a simplified example and the actual implementation of your custom indicator may be more complex depending on your needs.

If 'Tom' is having trouble accessing the value of the indicator, he can use the Current property of the indicator object, as shown in the example above. If the indicator is not updating correctly, he should make sure that he is calling the Update method with new data in the OnData method.

If 'Tom' is still having trouble, he may need to provide more specific details about the issue he is encountering.

I'm trying to use the example you gave to make sure I understand the concept (I'm pretty new to both python and Quantconnect) and I can't get it to build the project.  I must be missing something really simple.  just using the code you gave for my indicator it has red markers to the left of the init(self) def statement

Based on the information provided, it seems like 'Tom' is trying to create a custom indicator and use it in his algorithm. In QuantConnect, custom indicators are created by implementing the PythonIndicator class. This class must have an Update method and Name, Time, and Value attributes. The Update method should accept an IndicatorDataPoint, QuoteBar, or TradeBar and return a boolean that represents if the indicator is ready. The Time attribute represents the last time you updated the indicator and the Value attribute represents the current indicator value.

Here is an example of a custom simple moving average indicator:

class CustomSimpleMovingAverage(PythonIndicator):
 def __init__(self, name, period):
 self.Name = name
 self.WarmUpPeriod = period
 self.Time = datetime.min
 self.Value = 0
 self.queue = deque(maxlen=period)

 def Update(self, input: BaseData) -> bool:
 self.queue.appendleft(input.Value)
 count = len(self.queue)
 self.Time = input.Time
 self.Value = sum(self.queue) / count
 return count == self.queue.maxlen

To create an instance of this custom indicator, you can call the indicator constructor:

self.custom_sma = CustomSimpleMovingAverage("My SMA", 10)

To update the custom indicator, you can use the same process as updating manual indicators. If you want to access the current value of the indicator, you can use the Current.Value property:

current_value = self.custom_sma.Current.Value

If 'Tom' is still having issues, it would be helpful to know the exact error message he is receiving. It's also important to note that the red markers could be due to a syntax error or an issue with the Python interpreter settings in his development environment.