How to draw a line in Python Mayavi?

One important feature you can use when drawing lines is to represent them as a tube. The following example I used to draw the X, Y, Z axis along with the 3D figure (note that in my case the dimensions are big, so that you might want to adjust them):

import mayavi.mlab as mlab

black = (0,0,0)
white = (1,1,1)
mlab.figure(bgcolor=white)
mlab.plot3d([0, 1000], [0, 0], [0, 0], color=black, tube_radius=10.)
mlab.plot3d([0, 0], [0, 1500], [0, 0], color=black, tube_radius=10.)
mlab.plot3d([0, 0], [0, 0], [0, 1500], color=black, tube_radius=10.)
mlab.text3d(1050, -50, +50, 'X', color=black, scale=100.)
mlab.text3d(0, 1550, +50, 'Y', color=black, scale=100.)
mlab.text3d(0, -50, 1550, 'Z', color=black, scale=100.)

Check the documentation for mayavi; 3d plotting is in the tutorials and documented here. It's part of mlab, mayavi.mlab.plot3d(*args, **kwargs).

The syntax is

plot3d(x, y, z, ...)