python - watch function calls and variable values? -

how can watch functions called , variable values in python script?

i have discovered uncertainties package python, , want figure out how works can explain boss.

basically, can't see how uncertainties calculated. because don't know how python works yet.

for starters, how can see how c calculated?

import uncertainties uncertainties import ufloat  = ufloat(1,3) b = ufloat(2,4)  c = + b #how work??  print c 

you might take @ python debugger: http://docs.python.org/2/library/pdb.html

as may know, debugger designed let watch parts of program move during execution.

you might want take @ source code of uncertainties package @ https://github.com/lebigot/uncertainties/