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Sentdex's Quantopian Tutorial Updated (by me) for Quantopian 2: Algorithm 1 Videos 1-3

Since people seem to like Sentdex's tutorial for Quantopian, and they have not been updated for Quantopian 2- I thought updating them would be valuable to people here and a good way to finally learn Quantopian!

This first algorithm is a simple long-only trend following strategy. It highlights two of the major changes between Quantopian 1 and Quantopian 2 First, data[asset].mavg(days) has been replaced with data.history(asset, 'price', days, '1d').mean(). Second, his handle_data function should be replaced with a scheduled rebalance function.

Potential "Gotchya": When called before trading, like in before_trading_start, data.history(asset,'price', 10,'1d') does exactly what you expect: return the closing price for the previous 10 days. However, if it is called during trading, i.e. in either a handle_data call or scheduled rebalancd call, then it returns the most recent price observed in trading today and the closing price for the previous 9 days. (If you ever have questions about what's being returned, I found setting a debug-point and using get_datetime() to be useful to make sure I was working with the correct data.)

OH, and I much prefer my order entry logic and design pattern over his, but let me know if you feel otherwise.

Clone Algorithm
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Total Returns
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Alpha
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Beta
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Sharpe
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Sortino
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Max Drawdown
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Benchmark Returns
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Volatility
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Returns 1 Month 3 Month 6 Month 12 Month
Alpha 1 Month 3 Month 6 Month 12 Month
Beta 1 Month 3 Month 6 Month 12 Month
Sharpe 1 Month 3 Month 6 Month 12 Month
Sortino 1 Month 3 Month 6 Month 12 Month
Volatility 1 Month 3 Month 6 Month 12 Month
Max Drawdown 1 Month 3 Month 6 Month 12 Month
"""
This is the long-only trend following strategy developed in the first 3 videos
of Sentdex's tutorial.

This algorithm has been updated for Quantopian 2.

Original tutorial found here:
https://pythonprogramming.net/python-programming-finance-back-testing/?completed=/python-programming-creating-automated-trading-strategy/

"""
 
def initialize(context):
    """
    Called once at the start of the algorithm.
    """   
    
    context.security_list = [symbol('SPY')]
    # Rebalance every day, 1 hour after market open.
    schedule_function(my_rebalance, date_rules.every_day(), time_rules.market_open())
     
    # Record tracking variables at the end of each day.
    schedule_function(my_record_vars, date_rules.every_day(), time_rules.market_close())
    
 
def before_trading_start(context, data):
    """
    Called every day before market open.
    """
    prices200 = data.history(context.security_list, 'price', 200, '1d')
    prices50 = prices200[-50:]
    
    context.ma50 = ma50 = prices50.mean()
    context.ma200 = ma200 = prices200.mean()
    
    context.signal = (ma50 > ma200).to_dict()
    
    # These are the securities that we are interested in trading each day.
 
def my_rebalance(context,data):
    """
    Execute orders according to our schedule_function() timing. 
    """
    target_securities = sum( i for i in context.signal.values())
    for security, signal in context.signal.items():
        if signal and (security not in context.portfolio.positions):
            order_target_percent(security, 1./target_securities)
            log.info('Buying Shares')
        
        if (not signal) and (security in context.portfolio.positions):
            order_target_percent(security, 0)
            log.info('Selling Shares')
        
        
 
def my_record_vars(context, data):
    """
    Plot variables at the end of each day.
    
    NOTE: Recording moving averages really will not make sense if 
          you use more than one security in context.security_list.
          
          Recording leverage will still make sense.
    """
    record(MA1 = context.ma50, MA2 = context.ma200, leverage=context.account.leverage)

There was a runtime error.
5 responses

This is great. Cleared up my confusion. Thanks!

Great job. Thanks.

Thanks a lot!

Getting an AttributeError: ' bool' object has no attribute 'to_dict' in the before_trading_start method. Does anyone know why?

Awesome job, thanks for updating it and sharing with people. Just so you know, I'm currently re-doing the Quantopian series in the new finance series. We've not gotten to Quantopian yet, but it's coming, so I am not sure you'll want to keep updating it.

edit: I am seeing now that actually this was posted a long time ago, just happened to see it since it got a recent post, whoops.