The ornamental design for a base for a sweeper, as shown and described.
FIG. 1 is a front perspective view of a base for a sweeper showing our new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof, drawn to an enlarged scale; and,
FIG. 7 is a bottom plan view of FIG. 6.
The broken lines showing the connection of the upper portion of sweeper base to handle of the sweeper, as well as the broken lines showing the grid-work above the brush in the bottom plan view of FIG. 7 are included for the purpose of illustrating environmental structure, and form no part of the claimed design.