How can I define a function with default parameter values and optional parameters in Python?

Question

I want to define a function to which the input parameters can be omitted or have a default value.

I have this function:

def nearxy(x,y,x0,y0,z):
   d         


        

Answer 1

To specify a default value, define the parameter with a '=' and then the value.

An argument where a default value is specified is an optional argument.

For example, if you wanted x0,y0, and z to have default values of 1,2,3:

def nearxy(x,y,x0=1,y0=2,z=3):
   distance=[]
   for i in range(0,len(x)):   
       distance.append(abs(math.sqrt((x[i]-x0)**2+(y[i]-y0)**2)))
   ...
   return min(distance)

See http://docs.python.org/2/tutorial/controlflow.html#default-argument-values for more.