How can take input of n number of lists in python?

Question

How can we take input of n number of lists in python

for example

2
1 2 3
4 5 6 7

here 2 is specifying number of lists that are going to input

1 2 3 is one list

4 5 6 7 is second list

another example

3
1 2 3
4 5 6 8
2 3 5 7

3 indicates 3 lists are going to input

1 2 3 is list one
4 5 6 8 is list two
2 3 5 7 id list three

i have done this code

n=input()
for i in range(n):
    b=map(int,raw_input().split())

i am struck with this how can i take input for n number of lists i able to take only one list into one variable i want take to different different variables

Answer 1

i want take to different different variables

You can not assign the input to "different" variables in the loop, particularly if you do not know how large n will be. Instead, you should append the different values of b to a list of lists, eg bs .

n = input()
bs = []
for i in range(n):
    bs.append(map(int, raw_input().split()))

Or use a list comprehension:

bs = [map(int, raw_input().split()) for _ in range(n)]

Answer 2

do you want to read from file or cli?

If you read from file, you can iterate over its content line by line and work only in the specific lines.

The lines input you can split to get the single numbers into a list.

nums=[]
with open(infile.txt) as f:

 n=0
 for i, line in enumerate(f):
     if i==1:
          n == 1
     elif i <= n
         nums[i] = line.split()

Answer 3

There are a few things to fix:

1. You need to convert your input 'n' to an integer.
2. Your 'b' gets overwritten with every iteration of the loop.
3. Why are you using 'raw_input' in the second case? 'input' will give you a sanitized version of the input which is preferable in this case (so that a malicious user cannot inject code).

4. Keep it simple and use lists instead of a map.

    n = int(input()) rows = [] # will contain the input as a list of integers for i in range(n): row_string = input() row = [int(num) for num in row_string.split()] rows.append(row)