# python generator generates Yang hui triangle method of must see

• 2020-05-30 20:25:48
• OfStack

Writing interesting programs with Python feels good and can't stop

``````
# Generator generated display Yang hui 3 Angle
# Principle is in 1 a 2 The dimension array shows Yang hui 3 Angle, for the empty space 0 When output, is converted to ' '
def yang(line):
n,leng=0,2*line - 1
f_list = list(range(leng+2)) # Pre-distribution, insert At the beginning hu will slow down, at the bottom 1 Yes, right and left 1 A blank space
# All initialized to 0
for i,v in enumerate(f_list):
f_list[v] = 0
ZEROLIST = f_list[:] # The reserved 1 It's an array of all zeros
f_list[leng//2] = 1 # The initial of the first 1 line
re_list =f_list[:]
n=0
while n < line:
n = n+1
yield re_list
f_list,re_list = re_list[:],ZEROLIST[:]
start = leng//2-n # To calculate 1 The first in line 1 a 1 The location of the
end = start + 2*n # To calculate 1 Line of the last 1 a 1 The location of the
while start <= end:
re_list[start] = f_list[start - 1] + f_list[start+1] # Whether or not 1 , the position of the number, are up 1 Row the sum of the left and right digits at that position
start = start + 1
return 'done'

def printList(L):
n = 0
p_str = ''
for value in L:
ch = str(value)
if value == 0:
ch = ' '
p_str = p_str + ch
print(p_str)

for value in yang(8):
printList(value)``````

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