How to print a message box in python?

I'm trying to print out a message within a created box in python, but instead of it printing straight down, it prints horizontally.

def border_msg(msg):
    row = len(msg)
    columns = len(msg[0])
    h = ''.join(['+'] + ['-' *columns] + ['+'])
    result = [h] + ["|%s|" % row for row in msg] + [h]
    return result

Expected result

border_msg('hello')

+-------+
| hello |
+-------+

but got

['+-+', '|h|', '|e|', '|l|', '|l|', '|o|', '+-+'].

Here's a mildly elaborated function for printing a message-box with optional title and indent which centers around the longest line:

def print_msg_box(msg, indent=1, width=None, title=None):
    """Print message-box with optional title."""
    lines = msg.split('\n')
    space = " " * indent
    if not width:
        width = max(map(len, lines))
    box = f'╔{"═" * (width + indent * 2)}╗\n'  # upper_border
    if title:
        box += f'║{space}{title:<{width}}{space}║\n'  # title
        box += f'║{space}{"-" * len(title):<{width}}{space}║\n'  # underscore
    box += ''.join([f'║{space}{line:<{width}}{space}║\n' for line in lines])
    box += f'╚{"═" * (width + indent * 2)}╝'  # lower_border
    print(box)

Demo:

print_msg_box('\n~ PYTHON ~\n')

╔════════════╗
║            ║
║ ~ PYTHON ~ ║
║            ║
╚════════════╝

print_msg_box('\n~ PYTHON ~\n', indent=10)

╔══════════════════════════════╗
║                              ║
║          ~ PYTHON ~          ║
║                              ║
╚══════════════════════════════╝

print_msg_box('\n~ PYTHON ~\n', indent=10, width=20)

╔════════════════════════════════════════╗
║                                        ║
║          ~ PYTHON ~                    ║
║                                        ║
╚════════════════════════════════════════╝

msg = "And I thought to myself,\n" \
      "'a little fermented curd will do the trick',\n" \
      "so, I curtailed my Walpoling activites, sallied forth,\n" \
      "and infiltrated your place of purveyance to negotiate\n" \
      "the vending of some cheesy comestibles!"

print_msg_box(msg=msg, indent=2, title='In a nutshell:')

╔══════════════════════════════════════════════════════════╗
║  In a nutshell:                                          ║
║  --------------                                          ║
║  And I thought to myself,                                ║
║  'a little fermented curd will do the trick',            ║
║  so, I curtailed my Walpoling activites, sallied forth,  ║
║  and infiltrated your place of purveyance to negotiate   ║
║  the vending of some cheesy comestibles!                 ║
╚══════════════════════════════════════════════════════════╝

When you use list comprehension you get the output as list , as seen by your output, to see the new line character you need to print the result

And also you are using columns to multiply - which is only one for all strings. Change it to `row'

def border_msg(msg):
    row = len(msg)
    h = ''.join(['+'] + ['-' *row] + ['+'])
    result= h + '\n'"|"+msg+"|"'\n' + h
    print(result)

Output

>>> border_msg('hello')
+-----+
|hello|
+-----+
>>>