Index error due to the for-loop in python

Question

As I am new to python programming. I have a problem in the for loop with index error. I have gone through the suggestions that you have given me. My problem is that in the for loop... I didn't get any error with this code below...

for i in range(0,1):

But I have obtained an error if the limit exceeds for example (0,3)

for i in range(0,3):

The error is

IndexError: index 1 is out of bounds for axis 0 with size 1

I have tried to clear out this error and I am not sure that why this error occurs in the for loop if the limits exceed 1.

This is my code:

m=['paketone4000.dump.xlsx','paketone8000.dump.xlsx','paketone12000.dump.xlsx']
fig_name=['j4000','e8000','e12000']

fig=plt.figure(figsize=(6,6)) ##to obtain figure and dimensions of graph

for i in range(0,3):


    #ax=fig.add_subplot(111,projection='3d') ## to have a broad view of figure
    ax = fig.add_axes([0,0,1,1], projection='3d')

    #plot planes
    p = Rectangle((0,-0.7), 4.5,1.4, color="lightgrey", alpha=0.2) #plots the background frame
    ax.add_patch(p)

    art3d.pathpatch_2d_to_3d(p, z=0, zdir="z")

    j=pd.read_excel(m[i])  ##to read the excel file format
    X=j['x'] ## to import the variable on to axes from data set
    Y=j['y']
    Z=j['z']
    #ax.scatter(X,Y,Z,c='g', marker='o') ## to specify the color and shape of point(marker) of the frame

    a=j['x']##import centre of mass from excel file format
    b=j['y']
    c=j['z']

    q1=j['q1'], ##attaining quaternons from excel file format. (comma(,) transformed series to tuple)
    q2=j['q2'],
    q3=j['q3'],
    q4=j['q4'],

    m,n,o,p=np.array([q1,q2,q3,q4]) ## assigning quaternions to variables had converted tuple to float
    Rot_Mat=QtoR(m,n,o,p)

    #cuboid initialising parameters
    center = [a[0], b[0], c[0]] ##centre of the body
    length = 0.3 ##defining length, breadth, height
    width = 0.4
    height = 0.1
    side = np.zeros((8,3))  ###This numpy vector will be used to store the position of the sides

    #rotate the axes and update
    for angle in range(0, 360):
        ax.view_init(90, angle)

    cuboid(center, (length, width, height)) #to execute the defined cuboid

    plt.savefig(fig_name[i])
    plt.clf()
print("\nq1=",m,"q2=",n,"q3=",o,"q4=",p)
print('\nRotation Matrix=',Rot_Mat)
print ("\nCenter = \n",center)

My expected result is that I want to remove the error that was obtained and I am interested in to know why that error occurred when end limit is greater than one.

Answer 1

An image for this code execution. How about you try replacing

for i in range(0, 5):

with

for i in range(len(m)):

EDIT: Does this work?

m=['paketone4000.dump.xlsx','paketone8000.dump.xlsx','paketone12000.dump.xlsx']
fig_name=['j4000','e8000','e12000']

fig=plt.figure(figsize=(6,6)) ##to obtain figure and dimensions of graph

for index, i in enumerate(m):


    #ax=fig.add_subplot(111,projection='3d') ## to have a broad view of figure
    ax = fig.add_axes([0,0,1,1], projection='3d')

    #plot planes
    p = Rectangle((0,-0.7), 4.5,1.4, color="lightgrey", alpha=0.2) #plots the background frame
    ax.add_patch(p)

    art3d.pathpatch_2d_to_3d(p, z=0, zdir="z")

    j=pd.read_excel(i)  ##to read the excel file format
    X=j['x'] ## to import the variable on to axes from data set
    Y=j['y']
    Z=j['z']
    #ax.scatter(X,Y,Z,c='g', marker='o') ## to specify the color and shape of point(marker) of the frame

    a=j['x']##import centre of mass from excel file format
    b=j['y']
    c=j['z']

    q1=j['q1'], ##attaining quaternons from excel file format. (comma(,) transformed series to tuple)
    q2=j['q2'],
    q3=j['q3'],
    q4=j['q4'],

    m2,n,o,p=np.array([q1,q2,q3,q4]) ## assigning quaternions to variables had converted tuple to float
    Rot_Mat=QtoR(m2,n,o,p)

    #cuboid initialising parameters
    center = [a[0], b[0], c[0]] ##centre of the body
    length = 0.3 ##defining length, breadth, height
    width = 0.4
    height = 0.1
    side = np.zeros((8,3))  ###This numpy vector will be used to store the position of the sides

    #rotate the axes and update
    for angle in range(0, 360):
        ax.view_init(90, angle)

    cuboid(center, (length, width, height)) #to execute the defined cuboid
    amount_of_files_to_rename=index
    new_names = [i*1000 for i in range(4*amount_of_files_to_rename)[::4]]
    for i in new_names:
        plt.savefig('packetone {}.jpg'.format(i))

    #plt.savefig(fig_name[b])
    #plt.clf()       
print("\nq1=",m2,"q2=",n,"q3=",o,"q4=",p)
print('\nRotation Matrix=',Rot_Mat)
print ("\nCenter = \n",center)

Answer 2

You're using the name m for two different variables in your code. At the top of the file you use it to create a list of filenames, which you read in the loop. But later in the loop, you reassign it with this line:

m,n,o,p=np.array([q1,q2,q3,q4])

That causes the error when you try to read later files, as the new m value doesn't contain what the code expects (and may not be the expected size).

You should use two different variable names. This kind of issue suggest that it might be a good idea to use longer, more descriptive variable name, as you are a lot less likely to have this kind of random namespace collision with names like filenames and first_quaternion (or whatever).

I'd also suggest using range(len(m)) so that if you change the size of the list at some future time, you won't need to remember to also change the hard-coded range size.