Hey all, whenever my program runs, I get a runtime error on the line (weights = compute_weights(context, data)): TypeError: Expected assets argument to be of type or iterable of type Asset, ContinuousFuture, basestring. Im assuming the error is coming from within the compute_weights(context, data) method, but I have rewritten it over and over and I cannot solve the issue. Does anybody know where my program is going wrong? Thanks!!!

def compute_weights(context, data):

high_history = data.history(252,'1d','high')  

price = data.current(context.security, 'price')

# Find highest value in the past 52 weeks  

high = max(high_history[context.security][:-1]) 

# Weights are based on the relative difference current price and 52-Week High (252 Days = 52 Weeks)  
raw_weights = price / high

# Normalize our weights  
normalized_weights = raw_weights / raw_weights.abs().sum()

# Determine and log our long positions.  
long_secs = normalized_weights.index[normalized_weights > 0]

log.info("This week's longs: " + ", ".join([long_.symbol for long_ in long_secs]))

# Return our normalized weights. These will be used when placing orders later.  
return normalized_weights

def rebalance(context, data):
"""
This function is called according to our schedule_function settings and calls
order_target_percent() on every security in weights.
"""

# Calculate our target weights.  
weights = compute_weights(context, data)  


# Place orders for each of our securities.  
for security in context.security_list:  
    if data.can_trade(security):  
        order_target_percent(security, weights[security])

def record_vars(context, data):
"""
This function is called at the end of each day and plots our leverage as well
as the number of long and short positions we are holding.
"""

# Check how many long positions we have.  
longs = 0  
for position in context.portfolio.positions.itervalues():  
    if position.amount > 0:  
        longs += 1

# Record our variables.  
record(leverage=context.account.leverage, long_count=longs)