numpy.ndarray' object has no attribute 'append

Question

import numpy as np

Student1= [1,2]
test11= np.array([])
np.clip(0,1,20)
NOF=int(2) 
print("Enter test score, students name are (1,2,3, etc): ")
for i in range(NOF):
    data=int(input())
    test11.append(data)
total=0
for value in test11:
    total=total+value
print("The sum of all", total)

LIST VERSION

import numpy as np

Student1= [1,2]
test11= []
NOF=int(2) 
print("Enter test score, students name are (1,2,3, etc): ")
for i in range(NOF):
    data=int(input())
    test11.append(data)
total=0
for value in test11:
    total=total+value
print("The sum of all", total)

This keeps erroring 'numpy.ndarray' object has no attribute 'append.' I wanna be able to add user data, to the array test11. Works fine without making test11 a numpy array. But I wanna be able to limit the size of the number to 20. Any ideas? Plz make it simple.

ERROR CODE: Traceback (most recent call last): line 10, in test11.append(data) AttributeError: 'numpy.ndarray' object has no attribute 'append'

Answer 1

This seams to work. I changed a few lines again and marked them.

import numpy as np

Student1= [1,2]
test11= np.array([0])
NOF=int(2) 
print("Enter test score, students name are (1,2,3, etc): ")
data = None
while data is None:  # Remove this if you want the program to end if an error occurres.
    for i in range(NOF):
        try:  # Be sure the input is a int.
            data=np.array([int(input())])
            if data > 20:  # Be sure the input is <= 20.
                data = None  # If greater then 20. Turn data into None
                test11 = np.array([0])  # Empty the array.
                print("Error")
                break  # Then break out of the loop
            test11 = np.append(data, test11)
        except ValueError:
            data = None  # If it is not a int, data will trun into None
            test11 = np.array([0])  # Empty the array.
            print("Error")
            break

if data is not None:  # If data is not None then find the sum.
    total=0
    for value in test11:
        total = test11.sum()  # Use the sum fuction, though  total=total+value  will also work.
    print("The sum of all", total)

List version.

# import numpy as np

Student1= [1,2]
test11= []
NOF=int(2) 
print("Enter test score, students name are (1,2,3, etc): ")
data = None  # Assign ahead of time.
while data is None:  # Remove this if you want the program to end if an 
error occurres.
    for i in range(NOF):
        try:  # Be sure the input is a int.
            data=int(input())
            if data > 20:  # Be sure the input is <= 20.
                data = None  # If greater then 20. Turn data into None
                test11.clear()  # Clear the list if an error occurres.
                print("Error")
                break  # Then break out of the loop
            test11.append(data)
        except ValueError:
            data = None  # If it is not a int, data will trun into None
            test11.clear()  # Clear the list if an error occurres.
            print("Error")
            break

if data is not None:  # If data is not None then find the sum.
    total=0
    for value in test11:
        total=total+value
    print("The sum of all", total)

This is as compacted as I could make it, without changing the entire thing, and keeping it similar to what you started with.

Now the user can't use a number over 20, or any letters, or an error will appear.

Answer 2

You can replace you line with np.append:

np.append(test11,data)

But appending to numpy array is costlier than appending to a list. I would suggest use list structure with append and at the end convert your list to numpy array using np.array

Here is a list version:

import numpy as np

Student1= [1,2]
test11= []
np.clip(0,1,20)
NOF=int(2) 
print("Enter test score, students name are (1,2,3, etc): ")
for i in range(NOF):
    data=int(input())
    test11.append(data)
test11 = np.array(test11)
total = test11.sum()
print("The sum of all", total)

Answer 3

Numpy arrays doesn't have 'append' method, they are supposed to be created with the shape and length that you will need. So in your case, the best way would be to make a list, append the values, and then creating the array:

import numpy as np 
Student1= [1,2] 
test11= []
np.clip(0,1,20) 
NOF=int(2) 
print("Enter test score, students name are (1,2,3, etc): ") 
for i in range(NOF): 
    data=int(input()) 
    test11.append(data)

test11 = np.array(test11)