Troubleshooting

Most PyPScript problems are not mysterious.

They usually come from one of four places:

• bad structure
• missing imports
• broken pattern order
• logic that is too broad or too restrictive

This page helps you debug the script itself.

Problem: The File Does Not Validate

Check these first:

• header present
• engine line present
• imports above strategy block
• meta block present
• default -> HOLD(...) present

Minimal valid structure:

#!pyp/1.0
engine: pyp-1.0

import indicators.sma
import functions.cross

strategy "valid" {
    fast_ma = sma.evaluate(close, 10)
    slow_ma = sma.evaluate(close, 20)

    patterns {
        cross(fast_ma, slow_ma) -> UP(confidence: 0.80)
        default -> HOLD(confidence: 0.95)
    }
}

meta {
    author: "PyP"
    version: "1.0.0"
    description: "Valid example"
}

Problem: “Undefined Variable”

You referenced a name before defining it.

Wrong:

patterns {
    trend_up and breakout -> UP(confidence: 0.82)
    default -> HOLD(confidence: 0.95)
}

Fix:

trend_up = above(close, trend_ma)
breakout = cross(close, fast_ma)

Problem: “Missing Import”

You used a function or indicator but never imported it.

Wrong:

trend_ma = sma.evaluate(close, 50)

without:

import indicators.sma

Problem: Everything Evaluates To HOLD

This usually means one of these:

• your conditions are too restrictive
• the entry rule can almost never be true
• one regime filter blocks every setup
• the script logic contradicts itself

Example of impossible logic:

patterns {
    above(rsi_value, 70) and below(rsi_value, 30) -> UP(confidence: 0.90)
    default -> HOLD(confidence: 0.95)
}

That condition can never happen.

Problem: One Rule Catches Everything

This is a classic ordering bug.

Wrong:

patterns {
    above(rsi_value, 50) -> UP(confidence: 0.65)
    above(rsi_value, 80) -> UP(confidence: 0.92)
    default -> HOLD(confidence: 0.95)
}

Fix:

patterns {
    above(rsi_value, 80) -> UP(confidence: 0.92)
    above(rsi_value, 50) -> UP(confidence: 0.65)
    default -> HOLD(confidence: 0.95)
}

Problem: Too Many Signals

Common causes:

• your first rule is too broad
• confidence is too generous
• there is no meaningful HOLD zone
• trend filter is too loose

Example of a broad rule:

patterns {
    above(close, trend_ma) -> UP(confidence: 0.75)
    below(close, trend_ma) -> DOWN(confidence: 0.75)
    default -> HOLD(confidence: 0.95)
}

That may be valid, but it is often too eager.

Try adding:

• momentum filter
• trigger condition
• neutral hold state

Problem: Too Few Signals

Common causes:

• too many stacked filters
• thresholds are too tight
• regime filter is always false

Example:

patterns {
    trend_up and long_momentum and volatility_ok and breakout and reclaim and not overbought and not extended -> UP(confidence: 0.90)
    default -> HOLD(confidence: 0.95)
}

That may be so selective it rarely triggers.

If the script never expresses its edge, simplify.

Problem: Long Side Works, Short Side Does Not

That is often a strategy design issue, not a syntax issue.

Ask:

• are long and short conditions actually symmetric
• do short thresholds make sense
• is one side missing a real trigger

Example:

patterns {
    trend_up and long_momentum and long_trigger -> UP(confidence: 0.82)
    trend_down -> DOWN(confidence: 0.82)
    default -> HOLD(confidence: 0.95)
}

The short side is much looser than the long side.

Problem: The Script Is Hard To Read

This is usually caused by giant inline expressions.

Refactor:

From:

patterns {
    above(close, sma.evaluate(close, 50)) and above(rsi.evaluate(close, 14), 55) and cross(close, sma.evaluate(close, 20)) -> UP(confidence: 0.85)
    default -> HOLD(confidence: 0.95)
}

To:

trend_ma = sma.evaluate(close, 50)
entry_ma = sma.evaluate(close, 20)
rsi_value = rsi.evaluate(close, 14)

trend_up = above(close, trend_ma)
momentum_up = above(rsi_value, 55)
entry_reclaim = cross(close, entry_ma)

patterns {
    trend_up and momentum_up and entry_reclaim -> UP(confidence: 0.85)
    default -> HOLD(confidence: 0.95)
}

Practical Debug Checklist

When a script behaves strangely, check:

1. does it parse
2. are all imports present
3. are all named variables defined before use
4. are stronger rules above weaker ones
5. do any rules overlap badly
6. do any rules contradict each other
7. is default -> HOLD(...) present
8. can each pattern be explained in plain English

Best Debugging Method

Reduce the script until it is obvious.

Start with:

• one trend variable
• one momentum variable
• one trigger

Then rebuild from there.

That is usually faster than staring at a giant expression.

Related Pages

• Validation
• Pattern Matching
• Best Practices