Hi guys, I am still new to pipeline. I have gotten some variables in my pipeline and they have been attached, now to the pipeline. I am now struggling to get them into a loop so I can purchase the stock.

from quantopian.pipeline import Pipeline
from quantopian.algorithm import attach_pipeline, pipeline_output
from quantopian.pipeline.data.builtin import USEquityPricing
from quantopian.pipeline.data import morningstar
from quantopian.pipeline.filters import Q500US
from quantopian.pipeline.factors import AverageDollarVolume,SimpleMovingAverage

def initialize(context):
spy=Q500US()

ev = morningstar.valuation.enterprise_value.latest  
mean_50 = SimpleMovingAverage(inputs=[USEquityPricing.close], window_length=50,mask=spy)  
mean_200 = SimpleMovingAverage(inputs=[USEquityPricing.close], window_length=200, mask=spy)  
cf=morningstar.cash_flow_statement.free_cash_flow.latest  
fin_health=morningstar.asset_classification.financial_health_grade.latest  
earnings=morningstar.balance_sheet.retained_earnings.latest  



pipe=Pipeline() 

ma_cross=mean_50>mean_200  
free_cash=cf.percentile_between(90,100)  
earn=earnings.percentile_between(90,100)  
mkt_cap =ev.percentile_between(90,100)  

looking for 90% percentile in mkt_cap, earnings, and free cash flow

pipe.set_screen(ma_cross & free_cash & earn & mkt_cap)  
pipe.add(free_cash,"fc")  
# Attach the pipeline to the algorithm (basically store the pipe object reference and give it a name for easy use later)  
pipe.add(fin_health,"fin_health")

attach_pipeline(pipe,'my_pipeline')  

def weight(context):
long_weight=1.0/len(context.longs)
return long_weight

def before_trading_start(context,data):
context.output=pipeline_output('my_pipeline')
print(context.output)

context.longs = context.output[context.output['fc']].index.tolist()

context.long_weight = weight(context)  

#how do I get context.longs in a loop?
print(context.longs)

def rebalance(context,data):

for stock in context.portfolio.positions:  
        if stock not in context.longs and data.can_trade(stock):  
            order_target_percent(stock,0)  
for stock in context.longs:  
        if data.can_trade(stock):  
            order_target_percent(stock,context.long_weight)