Python multiplication table school exercise

Question

I have a school exercise, but im struggling to understand how to do the multiplication table. Could someone please help me?

So depending on the number and columns_number the multiplication table has to be different. I have tried to solve this this way:

number1 = 4
column1 = 3

for row in range(column1):
   for y in range(10):
       print("0"+str(number1)+" "+"x"+"0"+"")

But i dont know what to put in the print statement. Could someone please explain me how to solve this exercise

Answer 1

It will be easier to understand if you break it down into its component parts.

First of all build a list of strings where each string represents a 'cell' in your multiplication table.

Once you have that you can handle the output formatting.

Something like this:

def mtable(x, c):
    vlist = []
    for i in range(1, 10):
        vlist.append(f'{x:02d} x {i:02d} = {x*i:02d}')
    for i in range(0, 10, c):
        print('\t'.join(vlist[i:i+c]))

mtable(4, 3)

Output:

04 x 01 = 04    04 x 02 = 08    04 x 03 = 12
04 x 04 = 16    04 x 05 = 20    04 x 06 = 24
04 x 07 = 28    04 x 08 = 32    04 x 09 = 36

Answer 2

You can try something like this,

def multiplication_table(num, columns):
  output = ""

  for i in range(1, 10):
    output += f"{num} x {i} = {str(num * i).zill(2)}"
    
    if i % columns == 0:
      output += "\n"
    else:
      output += "\t"

  return output

print(multiplication_table(8, 2))

Output -

8 x 1 = 08  8 x 2 = 16
8 x 3 = 24  8 x 4 = 32
8 x 5 = 40  8 x 6 = 48
8 x 7 = 56  8 x 8 = 64
8 x 9 = 72  

Answer 3

You need something to input numbers:

def get_number(text,rng):
    """Ask with 'text' until the given input is int()-able and 
    inside range 'rng'. Return the integer - present error and 
    loop if not an int input or outside of specified."""
    while True:
        try:
            t = input(text)
            n = int(t)
            if n in rng:
                return n
            print("Invalid number, use integer in", rng)
        except ValueError:
            print("Invalid number, use integer in", rng)

You need something to create the table - string concatenation is wasteful, so use lists instead and '--'.join("1","3"]) to joint them back into a string.

To format the numbers, use pythons Format Specification Mini-Language to right-align and pad numbers in strings:

def mult_table(num, times, cols):
    out = [[]]

    # calculate max width for spacing reasons
    maxw =len(str(num*times))
    for i in range(1, times+1):

        # add to last list inside out
        # format numbers right aligned '>' with leading '0' to 'maxw' digits
        out[-1].append( f"{num:>0{maxw}} x {i:>0{maxw}} = {num * i:>0{maxw}}")
        
        # if out's last list reached length you need a new line, add new []
        if len(out[-1])==cols:
            out.append([])

    # create the texts from your list of lists
    return '\n'.join('   '.join(e) for e in out)

Then you need to get some inputs:

n = get_number("What table? ", range(1,21))
t = get_number("Up to what multiplyer? ", range(1,51))
c = get_number("How many columns? ", range(1, n+1))

print(mult_table(n, t, c))

To get:

What table? 8
Up to what multiplyer? 12
How many columns? 3
08 x 01 = 08   08 x 02 = 16   08 x 03 = 24
08 x 04 = 32   08 x 05 = 40   08 x 06 = 48
08 x 07 = 56   08 x 08 = 64   08 x 09 = 72
08 x 10 = 80   08 x 11 = 88   08 x 12 = 96

What table? 13
Up to what multiplyer? 42
How many columns? 7
013 x 001 = 013   013 x 002 = 026   013 x 003 = 039   013 x 004 = 052   013 x 005 = 065   013 x 006 = 078   013 x 007 = 091
013 x 008 = 104   013 x 009 = 117   013 x 010 = 130   013 x 011 = 143   013 x 012 = 156   013 x 013 = 169   013 x 014 = 182
013 x 015 = 195   013 x 016 = 208   013 x 017 = 221   013 x 018 = 234   013 x 019 = 247   013 x 020 = 260   013 x 021 = 273
013 x 022 = 286   013 x 023 = 299   013 x 024 = 312   013 x 025 = 325   013 x 026 = 338   013 x 027 = 351   013 x 028 = 364
013 x 029 = 377   013 x 030 = 390   013 x 031 = 403   013 x 032 = 416   013 x 033 = 429   013 x 034 = 442   013 x 035 = 455
013 x 036 = 468   013 x 037 = 481   013 x 038 = 494   013 x 039 = 507   013 x 040 = 520   013 x 041 = 533   013 x 042 = 546

# handles bad input gracefully
What table? apple
Invalid number, use integer in range(1, 21)
What table? 42
Invalid number, use integer in range(1, 21)
What table?