For pleasant and effective rendering of diagrams, sometimes it is a good idea to pay attention to cap and join styles.
The cap style of a line is the shape of the end of the line. Styles are:
BUTT: The end of the line is cut
off square at a line that passes through the
endpoint.
PROJECTING: The end of the line is
cut off square, but the cut line projects past
the endpoint a distance equal to half the line's
width.
ROUND: The end describes a
semicircle centered on the endpoint.
The join style describes the shape where two line segments meet at an angle.
ROUND: The join is a circle
centered on the point where the adjacent
line segments meet.
BEVEL: A flat facet is drawn
at an angle intermediate between the angles
of the adjacent lines.
MITER: The edges of the adjacent
line segments are continued to meet at a sharp
point.
This illustration shows Tkinter's cap and join options. Small red squares indicate the nominal endpoints of the two connected line segments.
