CODEWITHSUNDEEP
pythonpython-3.xtypestuplesnonetype
Ryan Yong
Ryan Yong

Reputation: 53

Python - Why 2 different functions identify the same tuple as <class 'tuple'> while another function identifies the same tuple as None

So when I call 

plot_bounces( ball, numbounces, boxWH_tuple, circle=None )

where ball is an object, numbounces is an int, boxWH_tuple and circle are tuples, and put a print(type(circle)) statement in this function, it is a tuple. However, when I call update_ball(ball, boxWH_tuple, circle=None) an put a print(type(circle)) statement in this function, it is a nonetype. I don't understand why nor how to make it a tuple for both functions. This is just part of my code which seems to be problematic.

This is what I used to call plot_bounces 

plot_bounces(Ball(-1,0,0.1), 1, (3,2), ( (0,0) ,0.4) )

There's another script with class Ball which deals with the Ball object.

My main concern is why print(type(circle)) gives me class 'tuple' for the first print and class 'NoneType' for the second print. 

def plot_bounces(ball, numbounces, boxWH_tuple, circle=None):
    print(type (circle))
     #make space to store coordinates 
    xcoords = []
    ycoords = []
    #store the starting point 
    xcoords.append(ball.x)
    ycoords.append(ball.y)


    while numbounces>0 :
        #calls on update_ball and change the old values with new ones 

        update_ball(ball, boxWH_tuple, circle=None)
#       
        ball=update_ball(ball, boxWH_tuple, circle=None)

        xpoint = ball.x
        ypoint = ball.y

        ycoords.append(ypoint)
        xcoords.append(xpoint)

        numbounces+= -1


def update_ball(ball, boxWH_tuple, circle=None):
    print (type(circle))

Should't it be a tuple for both cases?

Upvotes: 0

Views: 67

Answers (1)

rrawat
rrawat

Reputation: 1149

When calling update_ball() from plot_bounces(), please remove =None after circle, because when you do circle=None in a call (call, not function definition), then you are passing that argument as a None and therefore the confusion.

The call should be update_ball(ball, boxWH_tuple, circle)

Upvotes: 1

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