it' also possible to change the type size and line width used in plots this can be done using keyword arguments in individual calls to functionse the code principal #initial investment interestrate years values [for in range(years )values append(principalprincipal +principal*interestrate pylab plot(valueslinewidth pylab title(' growthcompounded annually'fontsize 'xx-large'pylab xlabel('years of compounding'fontsize ' -small'pylab ylabel('value of principal ($)'produces the intentionally bizarre-looking plot it is also possible to change the default valueswhich are known as "rc settings (the name "rcis derived from the rc file extension used for runtime configuration files in unix these values are stored in dictionary-like variable that can be accessed via the name pylab rcparams sofor exampleyou can set the default line width to points by executing the code pylab rcparams['lines linewidth' the point is measure used in typography it is equal to / of an inchwhich is mm