datalines_int = DataFrame({'rsparid': [1400, 634, 1508, 96, 161, 1011, 1007,
    518, 1955, 678]})
datalines_str = DataFrame({'rsparid': map(str, [1400, 634, 1508, 96, 161, 
    1011, 1007, 518, 1955, 678])})
datalines_int
Dataframe Merge in Pandas