Splitting DataFrame based off values [duplicate]

Solution for Splitting DataFrame based off values [duplicate]
is Given Below:

I have a DataFrame that I want to split into two different DataFrames so I can plot them with GeoPandas later.

    price       Latutude     Longitude  yr_built        geometry                pl
0   530000.0    -122.394    -122.394    1900    POINT (-122.39400 47.67000)     13.180632
1   740500.0    -122.368    -122.368    1900    POINT (-122.36800 47.69810)     13.515081
2   625000.0    -122.390    -122.390    1900    POINT (-122.39000 47.58720)     13.345507
3   595000.0    -122.345    -122.345    1900    POINT (-122.34500 47.65820)     13.296317
4   485000.0    -122.370    -122.370    1900    POINT (-122.37000 47.63850)     13.091904

There are yr_built that go from 1900-2015.

I tried to split it like this:

geoSub1910_1960 = pd.DataFrame()
geoSub1961_2015 = pd.DataFrame()

gdf['yr_built']= gdf['yr_built'].astype(int)

for i in range(len(gdf)):
    print(gdf.iloc[i,:])
    print('this is seperated')
    if gdf['yr_built'] <= 1960:
        geoSub1910_1960.append(gdf.iloc[i,:], ignore_index=True)
    else:
        geoSub1961_2015.append(gdf.iloc[i,:], ignore_index=True)

The Error that I get is:

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().