Multiple Array input in Python

Question

I Want to get multiple arrays, For example :

a(number of arrays)

Suppose let's say a=3

arr1[1,4,8,9....n]
arr2[2,4,9.....n]
arr3[2,6...n]

The values should be user inputs.

The issue here is the array will be repeated and the last value entered will be stored only..

Code so far:

def main():
 a=input("Enter the number of array's: ")
 k=1
 for _ in range(a):
 array = list(map(int, input("Enter %s'st array"%k).split())) 
 print(array)

• James: What have you tried so far? Please post your code.
• James: Please edit your post, as opposed to adding code in the comments
• accdias: You can solve the issue in your code using a list of lists instead.

Answer 1

The issue here is this part:

for _ in range(a):
 array = list(map(int, input("Enter %s'st array"%k).split()))

Every time you assign to array you overwrite the previous value that you stored. In order to keep all the arrays you create, you'll have to keep them in a separate list. Try something like this:

arrays = list()
for i in range(int(a)):
 arrays.append(list(map(int, input("Enter %s'st array" % (i + 1)).split())))
for array in arrays:
 print(array)

EDIT: You also weren't incrementing k, which means "Enter 1'st array" would come up for every prompt. Since you are in a loop anyway, you can use the loop variable (I have added this in as i) as the number in this prompt. You have to add 1 so that it starts at 1 and goes up, rather than starting at 0. Thanks for spotting that @accdias.

Also, you need to pass an integer to range(), and when you get input from the command line it will come in as a string. So, just call int() on it before passing it to range. I have edited the code above to reflect this.

• accdias: I guess that %k on input should be % a + 1 instead, right?
• Stack7: def main(): arrays = list() a = int(input("Enter number of arrays: ")) k = 0 for _ in range(a): arrays.append(list(map(int, input("Enter %s'st array"%k).split()))) for array in arrays: print(array)
• Stack7: for _ in range(a): NameError: name 'a' is not defined
• Rob Streeting: Have edited the code and added another note to the post as I noticed another bug.

Answer 2

def main():
 a=int(input("Enter the number of array's: "))
 size=int(input("Each array size: "))
 arrays=dict()
 for i in range(1, a+1):
 # arrays['array_'+str(i)]=[ j for j in range(1, size) lamda x: ]
 arrays['array_'+str(i)] = list(map(lambda j: int(input('value: ')), [ j for j in range(size)] ))
 print(arrays)

Hope this will help you

• Stack7: can you please explain arrays=dict()?
• Sachin: dict is a build-in class I have created the empty dict object with reference arrays, instead of doing, arrays = {}
• Stack7: instead of dict can we use list?
• Stack7: {'array_1': [1], 'array_2': [2], 'array_3': [3]} how to get a specific output let . say i want values of 'array_3'???
• Sachin: Yes, you can use list. Then your output will look like, [[1,2,3], [4,5,6]] for that: my_array_list = list() for i in range(1, a+1): my_array_list.append(list(map(lambda j: int(input('value: ')), [ j for j in range(size)] )))