Yes, this is a homework task. But just please, if you're going to give me the code please tell me what you've done in detail. I am extremely new to this.
So the task is to print an ASCII diamond depending on what width the user inputs. I can do the first half of the diamond, just not the bottom half, for some reason I just cannot see how to do it.
Here's my code:
wid = int(input("Width: "))
i = 1
while i <= wid:
print(" " * (wid - i) + "* " * i)
i = i + 1
Which will output the following if wid = 5:
Width: 5
*
* *
* * *
* * * *
* * * * *
I tried to explain the code with comments. I hope it helps.
wid = int(input("Width: "))
#no. of lines will be double the width
#each loop prints a line.
for i in range(wid *2):
#first half of the diamond
if i<=wid:
no_of_spaces = wid - i
no_of_stars = i
print(" "*no_of_spaces + "* "*no_of_stars)
#next half of the diamond
else:
no_of_spaces = i - wid
no_of_stars = 2*wid - i
print(" "*no_of_spaces + "* "*no_of_stars)
i=1
j=input("ENTER NO =")
l=0
for i in range(i,j-((j/2)-1),1):
print (' ' * ((j+1)/2-i)+'*' *(i*2-1))
l=(j/2+1)
while (i==l):
i=1
for i in range(i,j,1):
print (' ' *((i*2)-i)+'*' *(j-i*2))
if [i==j-1]:
l=raw_input('<press enter to exit>')
You start with i = 1 and go until i > wid to make the top. To make the bottom of the diamond, you must do the reverse of what you did for the top. The code is easy, but I won't write it unless you want me to.
after your while
i=i-2
while i>0:
print(" "*(wid-i)+"* "*i)
i=i-1;
One method
The simplest way would probably be have two loops; one counting i up to width, another counting i back down to 1.
width = int(input("Width: "))
i = 1
while i < width:
print " " * (width-i) + "* " * i
i += 1
while i > 0:
print " " * (width-i) + "* " * i
i -= 1
This is a bit unattractive because it's a little clumsy, but it's simple.
Another method
Another method is to have have a loop that counts to twice the width, doing one of two things. What it does depends on if i has passed the point of maximum width or not. So it does 'up' and 'down' in the same loop, counting i from 1 up to width*2.
width = int(input("Width: "))
i = 1
while i < width*2:
if i < width:
print " " * (width-i) + "* " * i
else:
print " " * (i-width) + "* " * (2*width-i)
i += 1
This:
print " " * (width-i) + "* " * i
...is your code. Spaces count from width down to 0, *'s from 1 up to width.
And this:
print " " * (i-width) + "* " * (2*width-i)
...is the same thing but inverted. Spaces count from 0 back up to width, and the *'s go back down from width to 1. This comes into play when i exceeds width.
Width: 4
* # first half does this onward
* *
* * *
* * * *
* * * # second half does the rest downward
* *
*
And another
Another alternative, more complex way is to use a for loop on a list that contains numbers counting up and down. For example: [1, 2, 3, 2, 1]
To make this list, this code has to be. I know, it's a bit ugly:
rows = []
for i in range(1, max+1):
rows.append(i)
rows += rows[-2::-1]
Then, you see, we run the for loop off it.
width = int(input("Width: "))
rows = []
for i in range(1, width+1):
rows.append(i)
rows += rows[-2::-1] # takes a reversed list and adds it on to the end: [1, 2, 3, 2, 1]
for i in rows:
print " " * (width-i) + "* " * i
i iterates through each of the numbers in the rows list, which looks something like [1, 2, 3, 2, 1]. Then we just need one printing gizmo.
In python, there's almost always a shorter and less comprehensible way of doing for loops, and in this case, we can get rid of two extra lines by shortening the first for loop:
width = int(input("Width: "))
rows = [ i for i in range(1, width+1)] # Brain-bending way of doing a for loop
rows += rows[-2::-1]
for i in rows:
print " " * (width-i) + "* " * i
And if you're feeling a bit crazy, here's a mere two line version of the whole thing!
width = int(input("Width: "))
print "\n".join([ " "*(width-i) + "* "*i for i in [ i for i in range(1, width+1) ]+[ i for i in range(1, width+1) ][-2::-1] ])
But I don't recommend this style of coding in general.
Sorry, I got a bit carried away at the end... but the best thing I can say to you now is try everything and play around!
Hope that helps. :)
Since some good methods have been addressed, here are some fun little hacky solutions.
Here's one using Python 2.7 string.center just for shits.
import string
width = int(raw_input("Width:"))
for i in range(width):
print string.center(i * " *", width * 2 )
for i in range(width,0,-1):
print string.center(i * " *", width * 2 )
And here's an outrageous one that ouputs using HTML to center.
file = open('file.html','w')
file.write("<div align='center'>")
for i in range(width):
file.write(i * " *")
file.write("<br>")
for i in range(width,0,-1):
file.write(i * " *")
file.write("<br>")
file.write("</div>")
file.close()
import webbrowser
webbrowser.open("file.html")
check it out (for python 2.7x) :
Filled ASCII Diamond :
width = 1
width += int(raw_input('Width : '))
for i in range (1,width):
for j in range (width,i,-1):
print " ",
for j in range (1,i,1):
print " * ",
print
for i in range (width,1,-1):
for j in range (width,i,-1):
print " ",
for j in range (1,i,1):
print " * ",
print
This works!! But not in any Browser window . . .
