---
id: "M:cAlgo.API.FileAssociations.Contains(System.String)"
kind: "method"
type: "T:cAlgo.API.FileAssociations"
url: "https://help.ctrader.com/ctrader-algo/references/Plugin/FileAssociation/FileAssociations/Contains/"
---

> Documentation index for agents: https://help.ctrader.com/ctrader-algo/llms.txt · machine index: https://help.ctrader.com/ctrader-algo/api.json

# FileAssociations.Contains

Member of [FileAssociations](https://help.ctrader.com/ctrader-algo/references/Plugin/FileAssociation/FileAssociations/index.md).

## Contains(string fileExtension)

Checks if the specified file extension is already associated.

Environments: Desktop supported · CLI not supported · Cloud not supported.

- CLI: Available to plugins only, and plugins cannot run in the CLI.
- Cloud: Available to plugins only, and plugins cannot run in the cloud.

C#:

```csharp
bool Contains(string fileExtension)
```

Python:

```python
api.FileAssociations.Contains(fileExtension: str) -> bool
```

### Parameters

- `fileExtension` (`string`, Python `str`): File extension with dot, ex: .pdf

### Returns

`bool` — 

Available since cAlgo.API 5.1.

### Examples

C#:

```csharp
if (!FileAssociations.Contains(".mydata"))
    FileAssociations.Add(".mydata");
```

Python:

```python
if not api.FileAssociations.Contains(".mydata"):
    api.FileAssociations.Add(".mydata")
```