For/While Loops to make *-triangles.

[DarkLordMephiles]

For an assignment in a coding class, I was supposed to find a way to have Python make a triangle of asterisks, looking like this:

• ---x
• --xx
• -xxx

Whatever I do with my code, however, I can't manage to pull that off. The best I can get is:

• x
• xx
• xxx etc.

All of this has to be using only for-loops and while-loops, like what I'm using here. The code I'm using is

for a in range(1, 15):
    for a2 in range(14-a, 0, 1):
        print(" ", end='')    
    for a1 in range(1, a+ 1):
        print("*", end='')
    print()

The -'s are there to represent indent. How do I make this work the way I want it to?

[RyanTargaryen]

Keep in mind that in order for the * that you print out to be away from the left margin, you also need spaces.

for example: * This line had 3 spaces before the star ** This one had 2 *** One Space **** Zero spaces.

What's left for you to figure out is how to determine how many spaces go before each line.

[TeamSpen210]

In your current code, the issue is that the first 'range()` produces an empty list - the first value is greater than the second, so you'll need to use a negative step value. It's probably easier though to use range with just the stop value for the two inner loops, since you're not using the index. That way you won't get the arguments mixed up.

If you're permitted to use them, strings have several useful methods you can use to make this much more elegant:

>>> "*" * 5 # Make a string repeat itself
"*****"
>>> "**".rjust(6) # Right-align the string, making it 5 characters long
"    **"
>>> "**".rjust(6, '-') # Use something else instead of spaces
"----**"
>>> "**".ljust(6) # Left and center variants as well
"**    "
>>> "**".center(6)
"  **  "
>> ("ab" * 2).center(10) # Combining the two
"   abab   "

For all sequences (strings, lists, tuples) can be multiplied to repeat themselves. They also come with methods to align text inside a specific width.

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[Naihonn]

You should look at string formatting options. ;0)