# FieldTrials

Field trials, which turn on experimental features of the WebRTC engine before it starts.

### *class* webrtc.interfaces.field_trials.FieldTrials

The field trials of the engine: a mapping of trial names to groups, like `{'WebRTC-Sctp-Snap': 'Enabled'}`.

Browsers take them from a command-line flag. Here, set them in `webrtc.field_trials`, or in the
`WRTC_FIELD_TRIALS` environment variable in the flag’s `Name/Group/` format, before the first
[`webrtc.RTCPeerConnection`](rtc_peer_connection.md#webrtc.interfaces.rtc_peer_connection.RTCPeerConnection) or [`webrtc.RTCIceTransport`](rtc_ice_transport.md#webrtc.interfaces.rtc_ice_transport.RTCIceTransport). They’re fixed from then on, for the life of
the process: a change raises [`webrtc.InvalidStateError`](../exceptions.md#webrtc.exceptions.InvalidStateError).

`str()` gives the `Name/Group/` format. Unknown names are accepted, and do nothing.

#### update(other: SupportsKeysAndGetItem[[str](https://docs.python.org/3/builtins/stdtypes.html#str), [str](https://docs.python.org/3/builtins/stdtypes.html#str)], /, \*\*kwargs: [str](https://docs.python.org/3/builtins/stdtypes.html#str)) → [None](https://docs.python.org/3/builtins/constants.html#None)

#### update(other: [Iterable](https://docs.python.org/3/library/collections.abc.html#collections.abc.Iterable)[[tuple](https://docs.python.org/3/builtins/stdtypes.html#tuple)[[str](https://docs.python.org/3/builtins/stdtypes.html#str), [str](https://docs.python.org/3/builtins/stdtypes.html#str)]], /, \*\*kwargs: [str](https://docs.python.org/3/builtins/stdtypes.html#str)) → [None](https://docs.python.org/3/builtins/constants.html#None)

#### update(\*\*kwargs: [str](https://docs.python.org/3/builtins/stdtypes.html#str)) → [None](https://docs.python.org/3/builtins/constants.html#None)

Sets several trials at once, or none of them if one is invalid.

#### clear() → None.  Remove all items from D.

### webrtc.interfaces.field_trials.field_trials *= FieldTrials({})*

The field trials of the process. See [`webrtc.FieldTrials`](#webrtc.interfaces.field_trials.FieldTrials).

### webrtc.interfaces.field_trials.fieldTrials *= FieldTrials({})*

Alias for [`field_trials`](#webrtc.interfaces.field_trials.field_trials)