N8n Code Python

---
name: n8n-code-python
description: Write Python code in n8n Code nodes. Use when writing Python in n8n, using _input/_json/_node syntax, working with standard library, or need to understand Python limitations in n8n Code nodes. 
category: Document Processing
source: antigravity
tags: [python, javascript, node, api, mcp, ai, workflow, template, document, rag]
url: https://github.com/sickn33/antigravity-awesome-skills/tree/main/skills/n8n-code-python
---


# Python Code Node (Beta)

Expert guidance for writing Python code in n8n Code nodes.

---

## ⚠️ Important: JavaScript First

**Recommendation**: Use **JavaScript for 95% of use cases**. Only use Python when:
- You need specific Python standard library functions
- You're significantly more comfortable with Python syntax
- You're doing data transformations better suited to Python

**Why JavaScript is preferred:**
- Full n8n helper functions ($helpers.httpRequest, etc.)
- Luxon DateTime library for advanced date/time operations
- No external library limitations
- Better n8n documentation and community support

---

## Quick Start

```python
# Basic template for Python Code nodes
items = _input.all()

# Process data
processed = []
for item in items:
    processed.append({
        "json": {
            **item["json"],
            "processed": True,
            "timestamp": datetime.now().isoformat()
        }
    })

return processed
```

### Essential Rules

1. **Consider JavaScript first** - Use Python only when necessary
2. **Access data**: `_input.all()`, `_input.first()`, or `_input.item`
3. **CRITICAL**: Must return `[{"json": {...}}]` format
4. **CRITICAL**: Webhook data is under `_json["body"]` (not `_json` directly)
5. **CRITICAL LIMITATION**: **No external libraries** (no requests, pandas, numpy)
6. **Standard library only**: json, datetime, re, base64, hashlib, urllib.parse, math, random, statistics

---

## Mode Selection Guide

Same as JavaScript - choose based on your use case:

### Run Once for All Items (Recommended - Default)

**Use this mode for:** 95% of use cases

- **How it works**: Code executes **once** regardless of input count
- **Data access**: `_input.all()` or `_items` array (Native mode)
- **Best for**: Aggregation, filtering, batch processing, transformations
- **Performance**: Faster for multiple items (single execution)

```python
# Example: Calculate total from all items
all_items = _input.all()
total = sum(item["json"].get("amount", 0) for item in all_items)

return [{
    "json": {
        "total": total,
        "count": len(all_items),
        "average": total / len(all_items) if all_items else 0
    }
}]
```

### Run Once for Each Item

**Use this mode for:** Specialized cases only

- **How it works**: Code executes **separately** for each input item
- **Data access**: `_input.item` or `_item` (Native mode)
- **Best for**: Item-specific logic, independent operations, per-item validation
- **Performance**: Slower for large datasets (multiple executions)

```python
# Example: Add processing timestamp to each item
item = _input.item

return [{
    "json": {
        **item["json"],
        "processed": True,
        "processed_at": datetime.now().isoformat()
    }
}]
```

---

## Python Modes: Beta vs Native

n8n offers two Python execution modes:

### Python (Beta) - Recommended
- **Use**: `_input`, `_json`, `_node` helper syntax
- **Best for**: Most Python use cases
- **Helpers available**: `_now`, `_today`, `_jmespath()`
- **Import**: `from datetime import datetime`

```python
# Python (Beta) example
items = _input.all()
now = _now  # Built-in datetime object

return [{
    "json": {
        "count": len(items),
        "timestamp": now.isoformat()
    }
}]
```

### Python (Native) (Beta)
- **Use**: `_items`, `_item` variables only
- **No helpers**: No `_input`, `_now`, etc.
- **More limited**: Standard Python only
- **Use when**: Need pure Python without n8n helpers

```python
# Python (Native) example
processed = []

for item in _items:
    processed.append({
        "json": {
            "id": item["json"].get("id"),
            "processed": True
        }
    })

return processed
```

**Recommendation**: Use **Python (Beta)** for better n8n integration.

---

## Data Access Patterns

### Pattern 1: _input.all() - Most Common

**Use when**: Processing arrays, batch operations, aggregations

```python
# Get all items from previous node
all_items = _input.all()

# Filter, transform as needed
valid = [item for item in all_items if item["json"].get("status") == "active"]

processed = []
for item in valid:
    processed.append({
        "json": {
            "id": item["json"]["id"],
            "name": item["json"]["name"]
        }
    })

return processed
```

### Pattern 2: _input.first() - Very Common

**Use when**: Working with single objects, API responses

```python
# Get first item only
first_item = _input.first()
data = first_item["json"]

return [{
    "json": {
        "result": process_data(data),
        "processed_at": datetime.now().isoformat()
    }
}]
```

### Pattern 3: _input.item - Each Item Mode Only

**Use when**: In "Run Once for Each Item" mode

```python
# Current item in loop (Each Item mode only)
current_item = _input.item

return [{
    "json": {
        **current_item["json"],
        "item_processed": True
    }
}]
```

### Pattern 4: _node - Reference Other Nodes

**Use when**: Need data from specific nodes in workflow

```python
# Get output