问题描述
我认为列举这样做会很方便：
def enumerate（itrbl，start = 0，step = 1）：
i = start
for itrbl：
yield（i，it）
i + = step
这允许比当前枚举更多的灵活性，
在许多情况下收紧代码，并且似乎它不会打破现有代码的b / b
。是的，我需要枚举的这种行为，比如今晚的
和当前的例子。我把步骤放在参数用于
概念对称与切片。
这是一个案例用途（或用例？）：
＃与提议的枚举对象
导入运算符
def in_interval（test，bounds，first = 1，reverse = False）：
op = operator .gt if reverse else operator.lt #python 2.5
bounds = sorted（bounds，reverse = reverse）
for i，绑定枚举（bounds，first）：
如果op（测试，绑定）：
返回i
返回i + 1
＃使用现有的枚举
导入运算符
def in_interval（test，bounds，first = 1，reverse = False）：
op = operator.gt if reverse else operator.lt #python 2.5
bounds = sorted（bounds，reverse = reverse）
for i，以枚举（bounds）绑定：
如果op（测试，绑定）：
返回i +第一个
返回i +第一个+ 1
py＃eg
....
pyin_interval（8，界限）
2
pyin_i nterval（1，bounds）
1
pyin_interval（1，bounds，reverse = True）
5
pyin_interval（8，bounds，reverse = True）
4
pyin_interval（20，bounds，reverse = True）
2
当然，我还没有用过这里的步骤。即使在这个简单的例子中，
提出的枚举也会清除代码和逻辑，从而消除了几个
加号。对于这个真实世界的例子，实际要求
反转垃圾箱会使提议的枚举提供的解混混淆。但是我认为可能很明显，
提出的枚举可能会比那个更复杂的情况有所帮助。
有什么想法吗？
James
I think that it would be handy for enumerate to behave as such:
def enumerate(itrbl, start=0, step=1):
i = start
for it in itrbl:
yield (i, it)
i += step
This allows much more flexibility than in the current enumerate,
tightens up code in many cases, and seems that it would break no
existing code. Yes, I have needed this behavior with enumerate, like
tonight and the current example. I put the "step" parameter in for
conceptual symmetry with slicing.
Here is a case use (or is it use case?):
# with the proposed enumerate
import operator
def in_interval(test, bounds, first=1, reverse=False):
op = operator.gt if reverse else operator.lt # python 2.5
bounds = sorted(bounds, reverse=reverse)
for i, bound in enumerate(bounds, first):
if op(test, bound):
return i
return i + 1
# with the existing enumerate
import operator
def in_interval(test, bounds, first=1, reverse=False):
op = operator.gt if reverse else operator.lt # python 2.5
bounds = sorted(bounds, reverse=reverse)
for i, bound in enumerate(bounds):
if op(test, bound):
return i + first
return i + first + 1
py# eg
....
pyin_interval(8, bounds)
2
pyin_interval(1, bounds)
1
pyin_interval(1, bounds, reverse=True)
5
pyin_interval(8, bounds, reverse=True)
4
pyin_interval(20, bounds, reverse=True)
2
Of course, I haven''t used step here. Even in this trivial example the
proposed enumerate cleans the code and logic, eliminating a couple of
plus signs. For this real-world example, the practical requirement for
reversing the bins obfuscates somewhat the de-obfuscation provided by
the proposed enumerate. But I think that it might be obvious that the
proposed enumerate could help significantly in cases a bit more
complicated than this one.
Any thoughts?
James
推荐答案
经过短暂的反思，我意识到我刚刚描述了一个
for-to-step-do风格循环可以在许多其他语言中找到，大多数
特别是BASIC。
James
After a brief reflection, I realized that I just described a
"for-to-step-do" style loop one might find in many other languages, most
notably BASIC.
James
'拼写了
izip（计数（开始），序列）
今天的Python。
that''s spelled
izip(count(start), sequence)
in today''s Python.
为什么这个函数'的工作为实际序列索引添加偏移量？
< / F>
why is it this function''s job to add an offset to the actual sequence index?
</F>
代码适用于经济学家。她坚持用
第一个bin开始为1.我猜，实际上，binning linerizes数据和
bin数可能会成为一个除数或者也许操作数
的对数。
James
The code is for an economist. She is insistent on starting with the
first bin as 1. I''m guessing, practically, binning linerizes data and
the bin number may potentially become a divisor or perhaps the operand
in a logarithm.
James
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