# Configuring Blackfire Continuous Profiler for Python

[Requires Production Plan](https://www.blackfire.io/pricing)

[configuring continuous profiling](https://www.youtube-nocookie.com/embed/1q_E6fk2Q1Q?rel=0&showinfo=0&modestbranding=1&autoplay=0)

The Python continuous profiling is currently made across 5 dimensions:

- **CPU Time**: time spent running on the CPU
- **Wall-time**: elapsed time per function call
- **Heap Live Size**: number of bytes allocated that are not yet garbage collected
- **Allocated memory**: number of bytes allocated in memory
- **Allocations**: time spent running on the CPU

## Requirements

- Python >= 3.7.0
- [Blackfire Agent](../up-and-running/configuration/agent) >= 2.13.0

## Installation

Get the [Blackfire Continuous Profiler Python library](https://github.com/blackfireio/python-continuous-profiling):

```bash
pip install blackfire_conprof
```

### Python continuous profiler API

The Python profiler API `Profiler` can be initiated with following options:

- `application_name`: the application name.
- `period`: specifies the length at which to collect CPU profiles. The default is 45 seconds.
- `upload_timeout`: observability data upload timeout. The default is 10 seconds.
- `labels`: a dict containing the custom labels specific to the profile payload that is sent.

The Python continuous profiler API has two functions:

```python
def start():
def stop():
```

#### `def start():`

The `start` function starts the continuous profiler probe. It collects profiling information in the background and periodically uploads it to the Blackfire Agent until the `stop` function is called.

#### `def stop():`

Stops the continuous profiling probe.

### A simple example application

#### 1/ Get the Blackfire Continuous Profiler Python library:

```bash
pip install blackfire_conprof
```

#### 2/ Create `example.py` with the following code:

```python
from blackfire_conprof.profiler import Profiler

def foo():
    import time
    time.sleep(1.0)

profiler = Profiler(application_name="my-python-app", labels={'my-extra-label': 'data'})
profiler.start()
foo()
profiler.stop()
```

#### 3/ Run the example application:

```bash
python example.py
```