Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
672 views
in Technique[技术] by (71.8m points)

python - Reverse upside-down asterisk triangle

I am trying to use nested for loops to ask the user for an integer and then the program will output a reverse, upside-down triangle, with the base of it having the number of asterisks and working its way down. It's supposed to look like this:

*****
 ****
  ***
   **
    *

The code I have:

def pattern():
  integer = requestInteger("Please enter a number")
  for number in range(0, integer):
    for variable in range(integer, 0, -1):
      if variable - 1 > number:
        sys.stdout.write(' ')
      else:
        sys.stdout.write('*')
  sys.stdout.write('
')

Outputs this:

    *
   **
  ***
 ****
*****

I'm not really sure how to go about changing my for loops around to make this work, and I've been trying for a while, so help would be much appreciated.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

You can use reversed range:

u=int(raw_input('Number:'))
for i in reversed(range(1,u)):
    print ' '*(u-i),'*'*i

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...