我正在通过 tuple_name[0]
访问一个长度为 2 的元组元素,但是 python 解释器一直给我错误 Index out of bounds
。
引用代码如下:
def full(mask):
v = True
for i in mask:
if i == 0:
v = False
return v
def increment(mask, l):
i = 0
while (i < l) and (mask[i] == 1):
mask[i] = 0
i = i+1
if i < l:
mask[i] = 1
def subset(X,Y):
s = len(X)
mask = [0 for i in range(s)]
yield []
while not full(mask):
increment(mask, s)
i = 0
yield ([X[i] for i in range(s) if mask[i]] , [Y[i] for i in range(s) if mask[i]])
x = [100,12,32]
y = ['hello','hero','fool']
s = subset(x,y) # s is generator
for a in s:
print a[0] # Python gives me error here saying that index out of
# bounds, but it runs fine if I write "print a".
最佳答案
将最后一行更改为简单地 print a
并运行您在上面粘贴的确切代码,我得到以下输出:
[]
([100], ['hello'])
([12], ['hero'])
([100, 12], ['hello', 'hero'])
([32], ['fool'])
([100, 32], ['hello', 'fool'])
([12, 32], ['hero', 'fool'])
([100, 12, 32], ['hello', 'hero', 'fool'])
所以,很明显,第一次迭代是一个空列表,因此 不 没有元素 0。
关于python - 访问元组的元素,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7637673/