Python - Automate code involving suffix
Both functions checkPolygon1 and checkPolygon2 perform essentially the same actions and only differ in specific polygon instance. That's an appropriate case for Parameterize Function refactoring technique where polygon instance can serve as a factor. 

Define a unified function point_in_polygon (don't forget about Python naming conventions):

def point_in_polygon(row, polygon):
    return polygon.contains(Point(row['X'], row['Y']))


Then, assuming that you already have a list or generator of polygons polygons:

for i, polygon in enumerate(polygons, 1):
    datacopy[f'InPolygon{i}'] = datacopy.apply(point_in_polygon, axis=1, polygon=polygon)