Are we playing any animations?

	// Plays an animation only if we are not playing it already.
	function OnMouseEnter() {
		if (!animation.isPlaying)
			animation.Play();
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void OnMouseEnter() {
        if (!animation.isPlaying)
            animation.Play();
        
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def OnMouseEnter() as void:
		if not animation.isPlaying:
			animation.Play()