定義一個函數(shù)畫棱形
def diamond(height):
"""Return a string resembling a diamond of specified height (measured in lines).
height must be an even integer.
"""
L=[]
line=''
s='/'
bs='\\'
for i in range(1,int(height/2+1)):
a=line.rjust(i,s).ljust(i*2,bs).center(height)
L.append(a)
for j in range(int(height/2),0,-1):
b=line.rjust(int(j),bs).ljust(j*2,s).center(height)
L.append(b)
for item in L:
line+=item+'\n'
return line
def diamond(height):
s = ''
# The characters currently being used to build the left and right half of
# the diamond, respectively. (We need to escape the backslash with another
# backslash so Python knows we mean a literal "\" character.)
l, r = '/', '\\'
# The "radius" of the diamond (used in lots of calculations)
rad = height // 2
for row in range(height):
# The first time we pass the halfway mark, swap the left and right characters
if row == rad:
l, r = r, l
if row < rad:
# For the first row, use one left character and one right. For
# the second row, use two of each, and so on...
nchars = row+1
else:
# Until we go past the midpoint. Then we start counting back down to 1.
nchars = height - row
left = (l * nchars).rjust(rad)
right = (r * nchars).ljust(rad)
s += left + right + '\n'
# Trim the last newline - we want every line to end with a newline character
# *except* the last
return s[:-1]
