CODEWITHSUNDEEP
pythonpython-3.xfor-loopprintingnested-lists
quarters
quarters

Reputation: 207

Print a nested list line by line - Python

A = [[1, 2, 3], [2, 3, 4], [4, 5, 6]]

I am trying my best to print A of the form:

1 2 3
2 3 4
4 5 6

That is in different lines, but I am unable to do so without all the elements in different lines. This is my code so far:

for r in A:
   for t in r:
       print(t,)
    print

This is my output:

1
2
3
2
3
4
4
5
6

It seems really simple, and I think a minor change would do it. Thanks!

Upvotes: 9

Views: 56489

Answers (9)

Albert G Lieu
Albert G Lieu

Reputation: 911

Better than the accepted answer

try this one liner [print(a) for a in A]; I love one liner! Give an upvote if you like it

A = [[1, 2, 3], [2, 3, 4], [4, 5, 6]]
[print(a) for a in A];
[1, 2, 3]
[2, 3, 4]
[4, 5, 6]

if you don't want to see [] in the printout, then do [print(*a) for a in A];

A = [[1, 2, 3], [2, 3, 4], [4, 5, 6]]
[print(*a) for a in A];
1 2 3
2 3 4
4 5 6

Upvotes: 5

Kartik Kapgate
Kartik Kapgate

Reputation: 11

for [a,b,c] in A:
   print(a,b,c)

This might help. But if you have more number of elements in the lists or if elements in the nested lists are variable,This won't work. Below code will print all elements of a nested lists in single line.

for b in A:
    for p in b:
         print(p,end=" ")
    print()

Upvotes: 1

Subham
Subham

Reputation: 411

Using yield from 

lst = [[1, 3, 4], [2, 5, 7]]
 
def f(lst ):
    yield from lst


for x in f(lst):
    print(*x) 

1 3 4
2 5 7

[Program finished]

Upvotes: 0

J.S.
J.S.

Reputation: 21

The same question was answered by Jim Fasarakis Hilliard in Print list of lists in separate lines.

In Python 3.x we can use: 

A = [[1, 2, 3], [2, 3, 4], [4, 5, 6]]

for i in A:
        print(*i)

And the corresponding output is:

1 2 3
2 3 4
4 5 6

Upvotes: 1

Rahul Gupta
Rahul Gupta

Reputation: 47866

Method-1 :

We can use list comprehension and .join() operator.

>>> my_list = [[1, 2, 3], [2, 3, 4], [4, 5, 6]]

>>> for item in my_list:
        print ' '.join(str(x) for x in item)

1 2 3
2 3 4
4 5 6

Method-2 :

>>> my_list = [[1, 2, 3], [2, 3, 4], [4, 5, 6]]

>>> for item in my_list:
        for x in item:
            print x,
        print 

1 2 3
2 3 4
4 5 6

Inner print with a comma ensures that inner list's elements are printed in a single line. Outer print ensures that for the next inner list, it prints in next line.

Upvotes: 2

James Mills
James Mills

Reputation: 19030

Use a simple for loop and " ".join() mapping each int in the nested list to a str with map().

Example:

>>> ys = [[1, 2, 3], [4, 5, 6], [7, 8, 9, 10]]
>>> for xs in ys:
...     print(" ".join(map(str, xs)))
... 
1 2 3
4 5 6
7 8 9 10

The difference here is that we can support arbitrary lengths of inner lists.

The reason your example did not work as expected is because your inner loop is iterating over each element of the sub-list;

for r in A:  # r = [1, 2, 3]
    for t in r:  # t = 1 (on first iteration)
        print(t,)
    print

And print() by default prints new-line characters at the end unless you use: print(end="") I believe if you were using Python 2.x print t, would work. For example:

>>> ys = [[1, 2, 3], [4, 5, 6], [7, 8, 9, 10]]
>>> for xs in ys:
...     for x in xs:
...             print x,
...     print
... 
1 2 3
4 5 6
7 8 9 10

But print(x,) would not work as you intended it; Python 2.x or 3.x

Upvotes: 10

Shashank
Shashank

Reputation: 13869

If you are in Python 3.x:

print(*('{} {} {}'.format(*r) for r in A), sep='\n')

or:

print(*('%d %d %d' % tuple(r) for r in A), sep='\n')

If not, you can import Python 3.x's print function from the __future__ module.

Upvotes: 1

lanpa
lanpa

Reputation: 1349

print without trailing comma will print a newline character.

for r in A:
    for t in r:
        print t,
    print

Upvotes: 1

abcd
abcd

Reputation: 10751

for r in A:
    print '%d %d %d' % tuple(r)

Upvotes: 2

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