Not entering short postions

Hey All,

I'm working on this simple algorithm that enters into longs and shorts based on moving averages. It is entering into long positions but not short. I can't seem to figure out why. Any help would be appreciated.

1
Backtest from to with initial capital
Total Returns
--
Alpha
--
Beta
--
Sharpe
--
Sortino
--
Max Drawdown
--
Benchmark Returns
--
Volatility
--
 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
# Backtest ID: 5a0dbe84782583437ed04731
There was a runtime error.
1 response

'shorts' -- always False. One thing is the 'and' won't do when combining True|False values in pipeline, and grouping with parens is important. Maybe begin with:

buy   = iso & (O_sma10 < 0) & (sma10 > 0)
short = iso & (O_sma10 > 0) & (sma10 < 0)


The debugger will be useful: https://www.google.com/search?q=debugger+site:quantopian.com
Click line number 100 and here are some example commands. (I've added some columns).

      columns={
'shorts': short,
'p_diff': p_diff,
'iso'   : iso,
'sma10' : sma10,
'O_sma10' : O_sma10,

len(pipe_results)
1498
pipe_results.tail()
DataFrame:
O_sma10    iso longs    p_diff shorts     sma10
Equity(32897 [NMX])     126.276500  False  True  0.003511  False  125.7374
Equity(32921 [SPR])      31.430000  False  True  0.033636  False   31.5030
Equity(34913 [RF])       37.309106  False  True  0.017522  False   37.4150
Equity(36930 [DISC_A])   16.147900  False  True  0.024425  False   16.1729
Equity(40069 [RBAK])     23.825200  False  True  0.269772  False   24.2650
pipe_results[(pipe_results.O_sma10 > 0) & (pipe_results.p_diff < 0)].tail()
DataFrame:
O_sma10    iso longs    p_diff shorts    sma10
Equity(32320 [JCG])   38.6089  False  True -0.010921  False  38.2609
Equity(32497 [HBI])   23.5190  False  True -0.014288  False  23.5490
Equity(32603 [WU])    22.4363  False  True -0.014521  False  22.4123
Equity(32618 [RVBD])  31.4018  False  True -0.000417  False  31.4498
Equity(32714 [LDOS])  17.9090  False  True -0.041563  False  17.8560