def getCRS(filePath):
    """
    extracts coordinatesystem from gml File 

    input "filepath": type string, file path to gml file 

    returns epsg code of used coordinate reference system: type list

    coordinatesystem= []
    ogr2ogr.main(["","-f", "GeoJSON", "outputCRS.json", filePath])
    myGeojson = pygeoj.load(filepath="outputCRS.json")
    properties= (myGeojson.get_feature(0).properties)
    for key, value in properties.items():     
        if key=="srsID":
            coordinatesystem.append(value)
        else:
            pass
    os.remove("outputCRS.json")
    if hf.searchForParameters(["crs","srsID"],coordinatesystem) is None:
        raise Exception('The gml file from ' + filePath + ' has no CRS')
    if hf.searchForParameters(["crs","srsID"],coordinatesystem,) == "4326" or "WGS84":
        return "4326"
    else:
        raise Exception('The gml file from ' + filePath + ' has no WGS84 CRS')
    return "4326"
    """
    return '4326'
