Question

#hello , i wounder why my code keep stoping at the secound while loop and doesn’t do anything

print"*******************************"
a = 0
deg_list =[]
deg_list_a=[]
deg_list_b=[]
deg_list_c=[]
degree=input("Enter the students Degree:")
while a<=degree:
    deg_list.append(degree);
    degree=input("Enter the students Degree:")
print "Degree List :",deg_list
print len(deg_list)
while len(deg_list)>=0:
    if deg_list[a]>=16:
        deg_list_a.append(deg_list[a])
        x=+1
    elif 15>deg_list[a]>=10:
        deg_list_b.append(deg_list[a])
        x=+1
    else :
        deg_list_b.append(deg_list[a])
        x=+1
print deg_list_a
print deg_list_b
print deg_list_c

Answer 1

Your code enters an endless loop.

Both of your while loops have problems with the condition which allows them to terminate. Since your code never changes the value of a, the first loop becomes while 0<=degree, and so the first loop terminates when the user inputs a negative value. But the variable a can be removed from your program.

The while loop continues as long as len(deg_list) >= 0. However, no code within the loop decreases the length of deg_list, so the while loop continues forever.

The code below could help you get this working:

deg_list =[]
deg_list_a=[]
deg_list_b=[]
deg_list_c=[]
degree=input("Enter the students Degree:")
while degree > 0:
    deg_list.append(degree);
    degree=input("Enter the students Degree:")
print len(deg_list)
while len(deg_list) > 0:        # Strictly greater than 0, not equal to 0.
    if deg_list[0] >= 16:
        # Use pop to access first element
        deg_list_a.append(deg_list.pop(0))    
    elif deg_list[0] >= 10:    # One comparison per statement, only.
        deg_list_b.append(deg_list.pop(0))
    else:
        deg_list_c.append(deg_list.pop(0))  # c, not b.
print deg_list_a
print deg_list_b
print deg_list_c